TWI659457B - Method for selectively doping three-dimensional substrate features on a substrate - Google Patents

Abstract

The invention provides a method for selectively doping three-dimensional substrate features on a substrate. A method, which may include: providing a substrate having a surface defining a substrate plane and substrate features extending from the substrate plane; directing an ion beam including angled ions to the substrate at a non-zero angle relative to a vertical line of the substrate plane, wherein the substrate A first portion of the feature is exposed to the ion beam, and wherein a second portion of the base feature is not exposed to the ion beam; the molecules of the molecular substance are directed to the substrate, wherein the molecules of the molecular substance cover the base feature; and the second substance is provided to interact with the molecular substance A reaction in which selective growth of a layer including a molecular substance and a second substance is performed such that a first thickness of the layer grown on the first portion is different from a second thickness of the layer grown on the second portion.

Description

Method for selectively doping three-dimensional substrate features on substrate

This application claims priority from US Provisional Patent Application No. 62/021491 filed on July 7, 2014, and further claims priority from US Patent Application No. 14/324907 filed on July 7, 2014.

Embodiments of the present invention relate to substrate processing, and more specifically, to a processing apparatus and method for depositing a layer by atomic or molecular beam deposition.

Many devices containing electronic transistors may have three-dimensional shapes that are difficult to process using conventional techniques. The phase of these devices may be upside down, concave, draped, or vertical with respect to the base plane of the substrate on which the devices are formed. In order to process such devices in order to grow layers on this phase, improved techniques that overcome the limitations of conventional processing may be useful. For example, substrate doping is often performed by ion implantation, where the surface of the substrate that can be effectively exposed to dopant ions is limited by the line-of-site trajectory of the ions. Therefore, vertical, concave, or overhanging surfaces may not be reachable by such dopant ions. It is with regard to these and other considerations that improvements of the present invention are needed.

This "Summary" is provided to introduce in simplified form a selection of concepts that are further described below in the "Detailed Description". This "Summary" is not intended to determine the key or essential characteristics of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

In one embodiment, a method may include providing a substrate having a surface defining a substrate plane and substrate features extending from the substrate plane. The method may further include directing an ion beam including angled ions to the substrate at a non-zero angle relative to a vertical line of a substrate plane, wherein a first portion of the substrate feature is exposed to the ion beam, and wherein the The second portion of the substrate feature is not exposed to the ion beam. The method may further include: directing molecules of a molecular substance to the substrate, wherein the molecules of the molecular substance cover the characteristics of the substrate; and providing a second substance to react with the molecular substance, wherein performing the step including The selective growth of the molecular substance and the layer of the second substance makes the first thickness of the layer grown on the first portion different from the second thickness of the layer grown on the second portion.

In another embodiment, a method of selectively doping three-dimensional substrate features on a substrate may include directing an ion beam including angled oxygen ions to the substrate at a non-zero angle relative to a vertical line of the substrate plane, Wherein a first portion of the substrate feature is exposed to the ion beam, and wherein a second portion of the substrate feature is not exposed to the ion beam. The method may further include A molecule is guided to the substrate, wherein the molecule of the molecular substance covers the characteristics of the substrate, wherein the ion beam is guided and the molecule is caused to generate a dopant oxide layer including the dopant at Selective growth on the first portion, but not selective growth on the second portion.

In another embodiment, a method of selectively doping three-dimensional substrate features on a substrate may include exposing the substrate to an oxide plasma, wherein the substrate features are covered by an oxygen sub-monolayer. The method may further include directing an ion beam including angled ions to the substrate at a non-zero angle relative to a vertical line of a substrate plane, wherein a first portion of the substrate feature is exposed to the ion beam, and wherein the The second portion of the substrate feature is not exposed to the ion beam, wherein the oxygen sub-monolayer is removed in the first portion, and the oxygen sub-monolayer remains in the second portion. The method may further include directing a molecule of a molecular substance comprising a dopant to the substrate, wherein the molecule of the molecular substance covers the substrate feature, wherein the directing the ion beam and directing the molecule A selective growth of a dopant oxide layer including the dopant is generated on the second portion, but not on the first portion.

100, 150, 200‧‧‧ processing equipment

102‧‧‧source assembly

104, 156‧‧‧ processing chamber

106, 312, 406‧‧‧ Angular Ions

108, 160, 204, 300, 400, 500, 600‧‧‧

110‧‧‧ molecular substance

112‧‧‧Assembly

152, 202‧‧‧ Plasma chamber

153, 302, 308‧‧‧ Plasma

154, 208‧‧‧ molecular sources

155‧‧‧ partition

158‧‧‧ base holder

162‧‧‧ Plasma source

163‧‧‧Applicator

164‧‧‧Gas source

168, 206, 362, 364, 506‧‧‧ ion beam

170‧‧‧ direction

174, 210, 324, 420‧‧‧ molecular beam

348, 504‧‧‧‧ Extraction of pores

178, 354, 502‧‧‧ Extraction plate

212, 304, 408, 508, 602‧‧‧ base features

214, 326, 608‧‧‧ optional layer

303‧‧‧ reactive ion

306, 414, 416 ‧‧‧ single-layer

310, 404‧‧‧ Plasma sheath boundary area

314, 410‧‧‧ exposed parts

316, 510, 604‧‧‧ sidewall

318‧‧‧Top surface

320, 412‧‧‧ Unexposed

322‧‧‧ lower surface

350‧‧‧ Extraction equipment

352‧‧‧beam stopper

356‧‧‧ Plasma sheath boundary

358, 360‧‧‧ meniscus

402‧‧‧oxygen plasma

422, 514‧‧‧ single layer

424‧‧‧Floor

512, 606‧‧‧ end wall

H‧‧‧ height

P‧‧‧plane

S‧‧‧Pitch

W‧‧‧Width

FIG. 1A depicts a processing device according to an embodiment of the invention.

FIG. 1B depicts details of another processing device according to an additional embodiment of the invention.

Figures 2A to 2D depict the use of processing device selection according to an embodiment of the invention A sequence of operations for sexual growth.

FIG. 2E illustrates a close-up of a portion before the processing operation according to FIGS. 2A to 2D.

FIG. 2F depicts the state of the substrate of FIG. 2E after processing via the operation sequence of FIGS. 2A to 2D.

3A to 3C illustrate exemplary operations involved in selectively depositing a layer in which horned ions are used to suppress deposition in an impacted portion of a substrate structure.

Fig. 3D depicts an alternative embodiment of the operation of Fig. 3B.

4A to 4C illustrate exemplary operations involved in the selective deposition of a layer, in which angularized ions are used to enhance deposition in an impacted portion of a substrate structure.

5A is a top view of a substrate for a selective deposition process and an extraction plate to provide an ion beam to the substrate.

FIG. 5B is a top view of the substrate of FIG. 5A after a molecular beam is provided following the ion beam.

FIG. 5C depicts a side view of the substrate in the same case as that shown in FIG. 5B.

6A and 6B depict a side view and an end view, respectively, of a substrate after being processed through multiple exposures to angled ions, according to additional embodiments.

Embodiments of the present invention relate to techniques for processing a substrate, including forming a thin layer on a substrate feature of the substrate. The base features of the base can extend from the base plane, And these structures can be formed into three-dimensional lines, fins, pads, pillars, walls, trenches, holes, vaults, bridges, cantilevers, other suspension structures, and the like. The embodiments are not limited in this regard. Furthermore, these features may be collectively or individually referred to herein as "three-dimensional" features. The thin layer formed on the substrate features may be a layer provided for doping, insulation, encapsulation, or other purposes.

In various embodiments, a thin layer may be formed by a modified atomic layer deposition or a modified molecular layer deposition process, and the technique may be used with conventional atomic layer deposition (ALD) or conventional molecular layer deposition (molecular layer deposition). , MLD) have common characteristics, except where indicated otherwise. Embodiments of the present invention provide a novel improvement over conventional ALD and MLD, which promotes formation on three-dimensional substrate features that may have poor surface configurations (such as the surface configurations described above).

In some embodiments such as using ALD or MLD to form a doped layer, a series of operations may be performed in which multiple layers are formed on a substrate that may include three-dimensional features. In addition, forming each layer may involve multiple operations, such as operations specific to ALD or MLD processes. In one embodiment, to dope the substrate with a deposited layer formed by ALD or MLD, the surface of the substrate features may first be cleaned to remove native oxides, which may involve the use of, for example, hydrogen, oxygen, and / or ammonia radicals and molecules Materials such as hydrides (such as nitrogen trifluoride, thallium, and phosphine) provide the plasma.

Second, a conformal plasma-enhanced atomic layer deposition of the dopant oxide can be performed to form a dopant oxide layer on the substrate features. This ALD process may involve the deposition of: arsenic, boron, phosphorus, arsenic oxide, phosphorus oxide, boron oxide, and / or doped Hetero-silicon oxides, such as silicon arsenic oxide, silicon phosphorus oxide, and silicon boron oxide. In particular, these oxides can be deposited using molecular precursors such as thorium, phosphine, and diborane, along with a plasma containing hydrogen, oxygen, nitrogen, and / or ammonia to generate an atomic beam.

In a subsequent operation, a combination of a molecular beam containing, for example, silane and another beam containing nitrogen, hydrogen, and / or ammonia can be used to deposit a sealing layer, such as silicon nitride. Once the native oxide is removed from the substrate features to be doped and a double layer of dopant oxide and sealing nitride is deposited, doping from the dopant oxide layer can be done using known techniques such as rapid thermal annealing The agent is driven into the substrate features.

In various embodiments of the present invention, the first thickness of the selectively formed layer in the first portion of the base feature may be made different from the second thickness of the layer in the second portion of the base feature to be selectively formed on the substrate. One or more layers are formed on the feature. For example, in an application for doping only a target portion of a three-dimensional base feature, a selective growth layer including a selectively grown dopant oxide material may be included on a first target portion of the three-dimensional base feature. Deposited to a target thickness, and on a second portion of the substrate feature outside the target portion, the dopant oxide material may be thin or absent. In this way, when the selectively grown layer is annealed to drive in the dopant, the region of the substrate feature adjacent to the target portion may be doped, thus forming a selectively doped region.

In various embodiments of the invention detailed below, this selection is facilitated by using angled ions that can be selectively guided to the first or target portion of the base feature without impacting the portion of the base feature outside the target portion Sexual deposition. Guidance of angular ions can be used in combination with other operations to form Novel ALD or MLD process for selectively growing one or more layers on a three-dimensional substrate feature. As used herein, the term "layer" may refer to a sub-monolayer, a single layer of a material, or may refer to a thin coating or film having a thickness of many single layers, unless otherwise indicated or accepted by context. Therefore, in some cases, a selectively grown "layer" may consist of a single monolayer formed on a target portion of a substrate, or may consist of multiple monolayers. In addition, according to various embodiments of the present invention, a layer having many single-layer thicknesses may be formed in a single-layer-single-layer manner as in a conventional ALD or MLD process. However, embodiments of the present invention also cover the selective growth of layers having a thickness of a plurality of single layers, where one layer is not grown in a single layer-single layer manner.

FIG. 1A depicts a processing device 100 configured in accordance with various embodiments of the present invention. The processing device 100 may be used to selectively grow a layer on a three-dimensional structure. The processing apparatus 100 includes a source assembly 102 and a processing chamber 104 adjacent to the source assembly. The source assembly 102 may include a plasma chamber (not shown separately) that generates a plasma that can be extracted into the corner ions 106 and provided to a substrate 108 disposed in the processing chamber 104. The source assembly 102 may further include a molecular source (not shown) that can provide a molecular beam (which may not be ionized) of the molecular substance 110 to the substrate 108. It should be noted that the molecular substance 110 may be composed of molecules that flow to the substrate 108 in a manner unique to the inert gas, and thus may not exhibit the directivity specific to the corner ions 106. In some embodiments, the source assembly 102 can include an additional plasma source that can provide additional ions (not shown) to the substrate 108 in an angled or non-angled manner. The source assembly 102 may further include an additional molecular source (not shown) to provide additional molecular species to the substrate 108. As detailed below, in some embodiments, the angled ions 106 and molecular substance 110 may be arranged in a manner that selectively promotes atomic layer growth of the overall layer in certain portions of the substrate, where the region in which layered growth occurs may undergo growth similar to that provided by conventional ALD or MLD Grow. In other embodiments, the horned ions 106 and the molecular species 110 may be provided in a manner that inhibits this atomic layer growth in the area impacted by the horned ions 106. Therefore, unlike conventional ALD or MLD techniques that can produce blanket, non-selective growth, the processing apparatus 100 facilitates the selective deposition of layers that can be formed on a single layer basis. This is achieved by treating the substrate with a combination of angular ions and molecules of a molecular substance. As detailed below, in various embodiments, the horn-forming ion may be an inert ion or a reactive ion.

As further illustrated in FIG. 1A, the assembly 112 is disposed between the source assembly 102 and the processing chamber 104. The assembly 112 may be composed of at least one plate or structure that provides gas communication between the source assembly 102 and a source in the processing chamber 104. For example, the assembly 112 may be composed of an extraction plate for extracting angular ions 106 from the plasma chamber and a shower head or similar structure for allowing the molecular substance 110 to flow to the substrate 108.

FIG. 1B depicts another processing device 150 according to an additional embodiment of the invention. The processing device 150 includes a plasma chamber 152 to form a plasma 153, a molecular source 154 to supply molecular substances, and a processing chamber 156 to receive a substrate holder 158 configured to support Or holding the substrate 160. The processing device 150 also includes a plasma source 162, which may include a plasma chamber power supply and an applicator 163 or electrode to generate a plasma according to known techniques. For example, in various embodiments, the plasma source 162 may be a field source or a remote source, coupled inductively A plasma source, a capacitively coupled plasma source, a helicon source, a microwave source, an arc source, or any other type of plasma source. The embodiments are not limited in this regard. When gas is supplied to the plasma chamber 152 through the gas source 164, the plasma source 162 may ignite the plasma 153, as illustrated. The plasma 153 may supply angled ions of the first substance in the form of an ion beam 168 to assist in selective deposition of a layer on substrate features.

As used herein, the term "angled" refers to, for example, a collection of ion plasmas in an ion beam, at least some of which are characterized by trajectories having a non-zero incident angle relative to a vertical line of the plane P of the substrate 160, as shown in Figure 1B As explained in. For example, referring to the illustrated Cartesian coordinate system, the angled ions may have a trajectory that forms a non-zero angle with respect to the Z axis.

In some embodiments, the substrate holder 158 is movable relative to the plasma chamber 152 in at least a direction 170 parallel to the Y-axis. In this manner, the substrate 160 can be moved from a position adjacent to the plasma chamber 152 to a position adjacent to the molecular source 154. Because of this movement, the substrate 160 may be alternately exposed to the ion beam 168 and the molecular beam 174 that may be formed as the molecules flow out from the molecular source 154. As detailed below, this can result in selective growth of the material layer by layer in the target portion of the three-dimensional base feature. As shown in FIG. 1B, it should be noted that physical isolation may be provided between different parts of the processing chamber 156 such that when the substrate 160 is adjacent to the molecular source 154, the substance from the plasma chamber 152 is separated from the substrate 160, And when the substrate 160 is adjacent to the plasma chamber 152, the substance from the molecular source 154 is separated from the substrate 160. This is shown as a separation wall 155.

In various embodiments, such as processing device 100 and processing device 150 Such processing equipment can operate at pressures lower than many conventional MLD or ALD systems. An exemplary pressure range includes 1 mTorr to 100 mTorr, under which the ion beam can be directed to the substrate without continuing to collide among the ions before hitting the substrate. This facilitates the ability to direct angled ions along a fixed trajectory to a target portion of a substrate feature, thereby allowing selective deposition of layers, as detailed below. Although FIG. 1B illustrates a processing device 150 in which the plasma chamber is separated from the molecular source, in various additional embodiments, an angular ion source such as a plasma chamber and a molecular beam source may be co-located so that the angular ions may be Substances as well as molecular substances are provided to the substrate to produce selective growth on the characteristics of the substrate without moving the substrate.

2A to 2D depict a sequence of operations for selectively growing a layer using the processing apparatus 200 according to an embodiment of the present invention. In this example, for purposes of illustration, the processing device 200 is illustrated in FIG. 2A to include a plasma chamber 202 that can provide angled ions to the substrate 204 in the form of an ion beam 206. The processing device 200 is also illustrated in FIG. 2B to include a molecular source 208 that can provide a molecular beam 210. As previously mentioned, this molecular beam may consist of molecules that flow to the substrate 204 in a non-directional manner. FIG. 2E illustrates a close-up of a portion of the substrate 204, which illustrates the substrate features 212 before processing. The description in FIG. 2F depicts the state of the substrate 204 including the substrate feature 212 after processing via the operation sequence of FIGS. 2A to 2D. In a specific example, the base feature 212 may constitute a fin structure that will be used to form a fin-type field effect transistor (finFET). As shown in FIGS. 2A and 2B, for example, the substrate 204 may be sequentially subjected to an ion beam 206 and a molecular beam 210 that direct the angled ions to the substrate 204. This sequence of operations can be used to form a layer of material (e.g., dopant oxygen Single layer of compound). This sequence of operations as illustrated in FIGS. 2A and 2B may be repeated in at least one additional processing cycle such as shown in FIGS. 2C and 2D to form additional material layers or a single layer of material. In particular, the angled ions of the ion beam 206 may selectively impact certain portions of the base feature 212 and may be prevented from impacting other portions of the base feature 212, as discussed in more detail below with respect to FIGS. 3A-4C. In combination with the molecules provided by the molecular beam 210, the result of this selective processing may be the formation of a selective layer 214, which is formed only on the upper portion of the base feature 212. The advantage of this method is that this selective formation of the selective layer 214 can facilitate selective doping of the upper portion of the base feature 212 without using a mask.

In an additional embodiment, instead of a molecular source, a remote plasma source may be used to provide a free radical species that is provided to the substrate 204 in an alternating manner with a guided ion beam that provides angled ions in order to characterize the substrate Selective formation of the layer occurs in the required part.

According to various embodiments of the present invention, horned ions may be used to selectively increase layer deposition or to selectively suppress layer deposition in areas impacted by horned ions. 3A to 3C illustrate exemplary operations involved in selectively depositing a layer in which horned ions are used to suppress deposition in exposed portions of a substrate structure. For illustrative purposes, it can be assumed that the layer to be grown is silicon oxide. However, in other examples, the layer to be grown may be a dopant oxide containing a dopant such as boron, phosphorus, or arsenic. In FIG. 3A, a case where the substrate 300 is exposed to reactive ions 303 that can be extracted from the plasma 302 is illustrated. The substrate 300 includes a substrate feature 304 that extends from a plane P of the substrate, as shown. The reactive ion may be oxygen, which is on the substrate feature 304 A sub-monolayer 306 is formed on the surface. In the context of forming a compound material by ALD or MLD (where the compound material includes two or more different elements, such as silicon oxide, etc.), a sub-monolayer may represent a layer of a first element, which may be a layer of a second element Reaction to form a monolayer of the compound. For example, during the deposition of a binary compound such as silicon oxide, a layer to be formed is deposited by repeating two different half cycles. After each half cycle, a fixed amount of reactive material supplied by the first precursor remains on the substrate surface. Ideally but not necessarily, a single monolayer of the first substance is produced after the first half cycle. In this context, this single monolayer of the first substance of the compound to be formed is called a "sub-monolayer" because the complete monolayer of the compound requires the addition of a second substance to react with the first substance. Therefore, the atoms of the sub-monolayer of the first substance may react with the atoms or molecules of the second substance supplied in the second half cycle. In each half cycle, after a given substance is supplied, a purge may be performed to remove any unreacted substance of the deposited material. The total amount of materials reacted in a cycle may therefore be equal to the sub-monolayer of each of the first substance or the second substance.

In a specific example, in an embodiment in which the substrate 300 is a semiconductor substrate such as silicon or silicon: germanium, the sub-monolayer 306 may be composed of oxygen bonded to silicon atoms on the surface of the substrate 300, and may subsequently be combined with silicon-containing molecules. Sub-monolayer reaction to form a monolayer of silicon oxide.

In FIG. 3B, a subsequent operation in which the angular ions 312 are guided to the substrate 300 when the substrate features 304 are covered by the sub-monolayer 306 is illustrated. Referring again to FIG. 1B, when ions such as hydrogen ions are extracted from the plasma via the extraction pores of the extraction plate 178, for example, angular ions 312 may be generated. Extraction plates are known to modify areas adjacent to extraction pores Plasma sheath boundary in the domain. This can cause curvature in the plasma sheath boundary, causing at least some ions to exit the plasma at an angle that is not perpendicular to, for example, the plane of the substrate. This situation is illustrated for the plasma 308, which is depicted for simplicity (the structural features of the plasma chamber are not depicted, such as the aforementioned extraction plate 178). As illustrated, the curved plasma sheath boundary region 310 may be formed next to the extraction pores (not shown), resulting in the generation of angular ions 312. It should be noted that although described as a pair of trajectories, the angled ions 312 may be characterized by an ion angular distribution. The term "ion angular distribution" refers to the average incidence angle of ions in an ion beam with respect to, for example, a reference direction perpendicular to the substrate, and the width or range of the distribution of the angle of incidence with the center at the average angle (referred to as "angular spread degree"). In some examples, the ion angular distribution may be a single mode, where the peak center of the number of ions that varies with the angle of incidence is approximately perpendicular to the plane P. In other examples, the ion angular distribution may involve an average angle forming a non-zero angle with respect to a vertical line of the plane P of the substrate 300. In a particular example, the ion angular distribution of the angular ions 312 may be a bimodal distribution of the angle of incidence. For example, in the example of FIG. 3B, the angled ions 312 may have trajectories in which the maximum number of trajectories are centered at two angular modes. In various embodiments, the degree of separation between the peaks of the bimodal distribution can be varied by controlling equipment settings such as plasma power and plasma chamber pressure. For example, the peak angle may be set at +/- 15 degrees relative to the vertical line of the plane P, +/- 30 degrees relative to the vertical line, +/- 45 degrees relative to the vertical line, or +/- 75 relative to the vertical line. The degree of angle illustrates several examples. However, the embodiments are not limited in this regard.

As a result, the angled ions 312 may affect a first portion of the substrate feature, which may be referred to as the exposed portion 314 of the substrate feature 304 and which includes the sidewall 316 and the upper region of the top surface 318. In some examples, the angled ion 312 may be a hydrogen ion that effectively reacts with oxygen to remove oxygen in the exposed area according to the reaction 2 H + 0> H ₂ O. In some examples, the angled ions may be inert gas ions. The angular ions 312 can be provided by effectively removing the ion energy and ion dose of the oxygen species constituting the sub-monolayer 306 in the exposed portion 314 as shown in the figure. However, due to the three-dimensional nature of the base feature 304, the angled ions 312 may be masked without hitting certain areas of the base feature (which is shown as the second part of the base feature 304 and may be referred to as the unexposed part 320) . For example, the first base feature may be obscured by an adjacent base feature such that the upper portion of the adjacent base feature blocks the angular ions 312 from impacting the lower portion of the first base feature. For example, the range of the unexposed portion 320 may vary depending on the angle of incidence of the angled ions 312, the distance S between adjacent substrate features, and the height H of the substrate features 304. The unexposed portion 320 may include a sidewall 316 and a lower region of the lower surface 322 as shown. Therefore, the sub-single layer 306 may remain intact in the unexposed portion 320.

In some embodiments, a beam stop (not shown) may be positioned inside the plasma chamber adjacent to the extraction aperture, which may have the effect of generating a pair of angled ion beams that may constitute a bimodal distribution of ions. Fig. 3D depicts an alternative embodiment of the operation of Fig. 3B. In this embodiment, the extraction device 350 is used to extract ions from the plasma 308 and direct the ions to the substrate 300. As illustrated, the extraction device 350 includes an extraction plate 354 that defines an extraction aperture 348. The beam stop 352 is positioned adjacent to the extraction aperture and within a plasma chamber (not shown). The beam stopper 352 and the extraction plate 354 together modify the shape of the plasma sheath boundary 356 so that the formation is depicted as a meniscus 358 And two meniscuses of meniscus 360. Ions exiting the plasma 308 from the meniscus 358 form an ion beam 362, and ions exiting the plasma 308 from the meniscus 360 form an ion beam 364. These two ion beams can impact the exposed portion 314 of the substrate feature 304 and prevent the formation of a sub-monolayer in a manner as described above with respect to the angled ions 312.

For a set of fixed base features in which the relative size, shape, and spacing of the base features remain unchanged, in order to change the range of the unexposed portion 320 in which the sub-single layer 306 remains intact, the gas pressure and plasma in the plasma chamber can be changed Power, extraction pore width, and other characteristics. These changes can change the shape of the plasma sheath boundary area, which in turn can change the angular distribution of ions into corner ions.

In a subsequent operation shown in FIG. 3C, a molecular beam 324 may be provided to the substrate 300. The molecular beam 324 may be provided in such a way that the substance of the molecular beam 324 hits all surfaces of the base feature 304. In the example of selectively forming silicon oxide, the molecular beam 324 may be composed of silane (SiH ₄ ) molecules or other silicon-containing molecules configured to react with the oxygen species of the sub-monolayer 306. The reaction of the silane with the oxygen in the sub-monolayer 306 may result in the formation of a monolayer of silicon oxide that is adhered to the substrate 300. The operations shown in FIGS. 3A, 3B, and 3C may be repeated to form additional single layers. In this manner, a selective layer 326 composed of silicon oxide may be formed in the unexposed portions 320 of the substrate features. However, in the oxygen-depleted exposed portion 314, the silicon oxide layer may not be formed because the required oxygen is absent, or the amount of silicon oxide formed may be reduced in proportion to the decrease in oxygen in the exposed portion 314. small.

In other embodiments, the sequence of operations shown in FIG. 3A to FIG. 3B may be generally followed. In addition to replacing the oxygen plasma, a nitrogen plasma may be provided to form a sub-monolayer of nitrogen, which It can then be selectively removed in the portion exposed to the angled ions. Subsequently, a silicon nitride monolayer can be formed by exposure to, for example, a silane molecular beam. The same applies to the selective formation of dopant oxide materials, in which molecular beams containing dopant molecules can be provided instead of silane to react with a sub-monolayer of the oxide remaining on the second or unexposed portion of the substrate feature .

4A to 4C illustrate exemplary operations involved in the selective deposition of a layer, in which angularized ions are used to enhance deposition in an impacted portion of a substrate structure. For illustrative purposes, it can be assumed that the layer to be grown is also silicon oxide. In the operation shown in FIG. 4A, it may be assumed that an oxygen plasma 402 is generated in a device containing an extraction plate that produces a curved plasma sheath boundary region 404. As illustrated, the angled ions 406, which may be oxygen ions, are extracted and directed to the substrate 400. The substrate 400 is characterized by a substrate feature 408 extending from the plane P, as shown. The angled ions 406 may strike the exposed portion 410 in the upper surface and in the upper region of the sidewall of the base feature 408. The unexposed portion 412 may not be impacted by the angled ions 406. Therefore, as shown in FIG. 4B, a sub-monolayer 414 of oxide may be formed in the exposed portion 410. In some cases, the unexposed portion 412 may still be exposed to some oxygen when the angular ions 406 are directed to the substrate 400. In this manner, some oxygen ions may form an oxygen-depleted sub-monolayer 416 that contains less oxygen species per unit area than the sub-monolayer 414. For example, the oxygen-depleted sub-monolayer 416 may contain 80% or 90% less oxygen species than the sub-monolayer 414.

Referring now to FIG. 4C, a subsequent operation of providing the molecular beam 420 to the substrate 400 is illustrated. In this operation, the molecular beam 420, which may be silane, may be present on the substrate Any oxygen species on feature 408 reacts. Therefore, a single layer 422 of silicon oxide may be formed in the exposed portion 410, while a smaller than a single layer deposition (shown as layer 424) may be formed on the unexposed portion 412. By properly adjusting the experimental conditions, it may be possible to completely suppress the formation of oxygen in the unexposed portion 412, so that the silicon oxide layer is only selectively deposited on the exposed portion 410.

In various additional embodiments, the extraction plate may be configured to provide additional selectivity for ALD growth, where single-layer growth may be limited to certain sides of the substrate feature and certain regions or portions of a given side of the feature. In these embodiments, a sidewall of a given base feature may constitute a first portion that receives horned ions, and an end wall of the base feature may constitute a second portion that does not receive horned ions. FIG. 5A is a top view of a substrate 500 and an extraction plate 502 for providing angular ions to the substrate as part of a selective deposition process for single layer growth. The extraction plate 502 includes extraction slits 504 elongated along the X axis. The extraction aperture 504 may, for example, extend the entire width W of the substrate 500 along the X axis so that ions can be guided along the entire width W in a given situation. By scanning the substrate 500 along the Y axis with respect to the extraction aperture 504, ions can be provided across the substrate.

In FIG. 5A, the ion beam 506 may be extracted via the extraction aperture 504 and directed toward the substrate 500 (to the page of FIG. 5A). The ion beam 506 is illustrated by different arrows, and its trajectory illustrates an exemplary trajectory of the ion beam as projected in the X-Y plane. It should be noted that the ions of the ion beam 506 may be angled with respect to the Z axis, as in FIG. 4A. As shown, most of the trajectories of the ions of the ion beam 506 are aligned parallel to the Y axis. A set of base features 508 are illustrated having a side wall 510 and an end wall 512 extending perpendicularly to the side wall 510.

Ions oriented with a trajectory parallel to the Y-axis may impact the sidewalls 510 of the base feature 508 oriented parallel to the X-axis. In contrast, the end wall 512 of the base feature 508 oriented parallel to the Y axis may receive little or no ion bombardment.

Where ion beam 506 includes angled ions (as in FIG. 4A) that effectively enhance single-layer growth, growth on end wall 512 may thus be selectively enhanced along side wall 510. Accordingly, a molecular beam that reacts with a portion of the substrate feature 508 that receives ion bombardment from the ion beam 506 may be provided in additional operations, as generally depicted in FIG. 4C. FIG. 5B is a top view of the substrate 500 after the molecular beam is provided following the ion beam 506. As shown, a single layer 514 is selectively formed along the side wall 510 but not along the end wall 512. This is further illustrated in FIG. 5C, which depicts a side view (rather than a cross-section) of the substrate 500 in the same case as that shown in FIG. 5B.

In the examples of FIGS. 5B and 5C, the angled ions are used to selectively process the side wall 510 with respect to the end wall 512 and selectively process the upper portion of the side wall with respect to the lower portion of the side wall. Thus, the examples of Figures 5B and 5C indicate the types of compound selectivity provided by embodiments of the present invention, where only certain portions of certain sides of the substrate feature are processed. However, other embodiments provide other types of selectivity. For example, in one embodiment, the entire sidewall, rather than just the upper region of the sidewall, may be exposed to angled ions.

In other examples, the entire end wall may be exposed to the angled ions, while only the upper region of the side wall is exposed to the ions. Figures 6A and 6B depict examples of this type of selective monolayer growth. 6A and 6B depict a side view and an end view of a substrate 600 having a substrate feature 602 with a selective layer 608 grown, respectively. Selective layer 608 A monolayer of a plurality of monolayers grown during the process generally depicted in Figures 4A to 4C, wherein selective growth is promoted by exposure to angular ions. As shown, the selective layer 608 completely covers the end wall 606 and the upper portion of the side wall 604. This can be achieved by guiding the angular ions (not shown) via the extraction plate in a first exposure where the end wall 606 is arranged parallel to the trajectory of the angular ions, and rotating the substrate 600 in the XY plane by 90 Degrees, and guide the angular ions in a second exposure where the trajectories of the angular ions are parallel to the side wall 604.

In addition, instead of promoting single-layer growth on certain sides of the substrate features exposed to the angled ions as shown in FIGS. 5B and 5C, the angled ions can be used to suppress the Single layer growth on those sides.

In other embodiments, instead of providing an oxygen ion beam, horny nitrogen ions can be directed to substrate features to selectively form a sub-monolayer of nitride that effectively reacts with silane to form a selectively deposited silicon nitride layer. In addition, in other embodiments, instead of providing a molecular beam of silane, in the operation shown in FIG. 4C, a molecular beam containing a dopant may be provided to react with an oxide sub-monolayer to form a dopant oxide. Selective deposition of layers.

In the manner described above, embodiments of the present invention can be used to selectively form a layer in a target portion of a substrate feature by using angular ions. As mentioned, embodiments of the present invention provide the flexibility to enhance or inhibit the formation of layers in the portions that are impacted by ions. This allows different regions of the base feature to be targeted for selective growth, such as the upper or lower regions of the base feature.

Although the above examples illustrate the formation of silicon oxide, embodiments of the present invention expand Extend to form doped oxides, nitrides, and other materials that can be formed in a layer-by-layer process. In addition, embodiments of the present invention can be used to selectively deposit layer stacks of different materials on a base structure. This layer stack may include, for example, a doped oxide layer and an encapsulated nitride layer, which may be used in the process of forming a doped region in an underlying substrate feature.

The scope of the invention should not be limited by the specific embodiments described herein. Indeed, those of ordinary skill in the art will appreciate (in addition to those embodiments and modifications described herein) various other embodiments of the invention and modifications to the invention based on the above description and the accompanying drawings. Accordingly, such other embodiments and modifications are intended to be within the scope of the invention. In addition, although the invention has been described herein in specific contexts for specific purposes, in the context of specific embodiments, one of ordinary skill in the art will recognize that the utility of the invention is not limited in this regard, and that the invention may be advantageously used in many It is implemented in the environment for many purposes. Accordingly, the scope of patenting set forth below should be interpreted in light of the entire breadth and spirit of the invention as described herein.

Claims (15)

A method for selectively doping a three-dimensional substrate feature on a substrate, comprising: providing a substrate having a surface defining a substrate plane and a substrate feature extending from the substrate plane; a vertical line with respect to the substrate plane is not Zero angle directs an ion beam including angled ions to the substrate, wherein a first portion of the substrate feature is exposed to the ion beam, and wherein a second portion of the substrate feature is not exposed to the ion beam; Molecules of a molecular substance are guided to the substrate, wherein the molecules of the molecular substance cover the characteristics of the substrate; and a second substance is provided to react with the molecular substance, wherein proceeding includes the molecular substance and the second substance The selective growth of the layer of matter is such that a first thickness of the layer grown on the first portion is different from a second thickness of the layer grown on the second portion. The method for selectively doping a three-dimensional substrate feature on a substrate according to item 1 of the patent application scope, further comprising providing the second substance as a reactive ion to the substrate before guiding the angled ions. , Wherein the reactive ions form a sub-monolayer on the substrate feature, wherein the angled ions remove the sub-monolayer on the first part, and wherein the layer on the second part The second thickness of is greater than the first thickness of the layer on the first portion. The method for selectively doping a three-dimensional substrate feature on a substrate according to item 2 of the scope of the patent application, wherein the reactive ion is oxygen and the molecule is a silane. The method for selectively doping a three-dimensional substrate feature on a substrate as described in item 1 of the patent application scope, wherein the angled ions include a reaction constituting the second substance and configured to react with the molecular substance And the first thickness of the layer on the first portion is greater than the second thickness of the layer on the second portion. The method for selectively doping a three-dimensional substrate feature on a substrate according to item 4 of the scope of the patent application, wherein the angle-forming ion is an oxygen ion or a nitrogen ion, and the molecule is a silane. The method for selectively doping a three-dimensional substrate feature on a substrate according to item 1 of the scope of patent application, further comprising modifying a plasma sheath boundary to generate the angled ions. The method for selectively doping a three-dimensional substrate feature on a substrate according to item 1 of the scope of patent application, wherein the ion beam to the substrate and directing the molecules of the molecular substance to the substrate include An effective processing cycle for selectively depositing a single layer of a compound including the molecular substance and the second substance. The method for selectively doping a three-dimensional substrate feature on a substrate as described in item 1 of the scope of patent application, wherein the second portion is masked by a second substrate feature, and wherein the angled ions do not strike the second section. The method for selectively doping a three-dimensional substrate feature on a substrate according to item 1 of the scope of the patent application, wherein the layer is a selectively grown dopant oxide, wherein the first thickness is greater than the first thickness. With two thicknesses, the method further includes annealing the substrate, wherein a selectively doped region is formed in the substrate feature adjacent to the first portion. The method for selectively doping a three-dimensional substrate feature on a substrate according to item 1 of the scope of patent application, wherein the second thickness is zero. The method for selectively doping a three-dimensional substrate feature on a substrate according to item 1 of the patent application scope, wherein the substrate feature includes a side wall and an end wall extending vertically to the side wall, wherein guiding the ion beam includes An extraction aperture is provided in an extraction plate extending along a first direction parallel to the sidewall, wherein the angled ions impact the sidewall without impacting the end wall, and wherein the sidewall includes the first A portion, and the end wall includes the second portion. A method for selectively doping three-dimensional substrate features on a substrate, comprising: directing an ion beam including angled oxygen ions to the substrate at a non-zero angle relative to a vertical line of a substrate plane, wherein the three-dimensional substrate A first portion of a feature is exposed to the ion beam, and wherein a second portion of the three-dimensional substrate feature is not exposed to the ion beam; a molecule of a dopant-containing molecular substance is directed to the substrate, wherein the The molecules of the molecular substance cover the three-dimensional base feature, wherein the ion beam is guided and the molecules are guided to produce a selective growth of a dopant oxide layer including the dopant on the first portion, But not selective growth on the second part. The method for selectively doping a three-dimensional substrate feature on a substrate according to item 12 of the patent application scope, further comprising annealing the substrate, wherein a doped region is formed on the three-dimensional substrate adjacent to the first portion. Features. A method for selectively doping a three-dimensional substrate feature on a substrate, comprising: exposing the substrate to an oxide plasma, wherein the three-dimensional substrate feature is covered by a single layer of oxygen; a vertical line relative to a plane of the substrate An ion beam including angled ions is directed to the substrate at a non-zero angle, wherein a first portion of the three-dimensional base feature is exposed to the ion beam, and wherein a second portion of the three-dimensional base feature is not exposed to The ion beam, wherein the oxygen sub-monolayer is removed in the first part, and the oxygen sub-monolayer remains in the second part; the molecules of the molecular substance containing the dopant are guided to the The substrate, wherein the molecules of the molecular substance cover the three-dimensional substrate feature, wherein the ion beam is guided and the molecule is guided to generate a dopant oxide layer including the dopant on the second Selective growth on part, but not selective growth on the first part. The method for selectively doping a three-dimensional substrate feature on a substrate according to item 14 of the patent application scope, further comprising: depositing a sealing layer on the substrate; and annealing the substrate, wherein the doped regions are adjacent The second portion is formed in the three-dimensional base feature.