TW200527665A - Capacitive pressure sensing member and a method for manufacturing the same - Google Patents

Abstract

In a capacitive pressure sensing member of the invention, a fixed bottom electrode plate is mounted to a base layer. A suspended top electrode plate is suspended above the fixed bottom electrode plate, and a gap and a parallel-plate sense capacitor are formed between the two electrode plates. A first dielectric layer having a central portion and a surrounding portion covers over the base layer and the electrode plates. The surrounding portion is formed with top metal plugs electrically connected to the top electrode plate. A top metal composite layer is formed on the surrounding portion and electrically connected to the top metal plugs. A passivation layer covers over the surrounding portion and the metal composite layer. At least one etching hole opened through the first dielectric layer and the top electrode plate connects with the gap and is hermetically sealed by a sealing plug. Thus, the thickness of the composite suspended structure may be effectively reduced, and the sensing effect may be enhanced.

Description

200527665 V. Description of the invention (1) [The method of the invention to which the invention belongs, especially the integrated electric quantity measurement of pressure sensing related to the sensing effect, and the patent application date is 90 pieces of the Republic of China and its manufacturing book number is Issue No. 91106806 capacitive fingerprint reading 91110443, technical field of fingerprint reading] It is about the structure and manufacture of a capacitive pressure sensing element in a better capacitive pressure sensing that is not easily affected by temperature and moisture noise. The structure and manufacturing method of the element, the capacitor is made of a capacitive pressure sensing array element using micro-processing technology & CMOS integrated circuit manufacturing process, which can be used as a tactile pressure signal and can be applied to a fingerprint sensor. The present invention is related to the following: 1. The Republic of China Invention Patent Application No. 9 011 2 0 2 3, the application date was May 17, and the name of the invention is "Capacitive Pressure Micro-sensing Element Method and Flood Number Reading Method" , Has obtained a patent, bean certification patent No. 1 82 652; 2. The Republic of China invention patent / application 'The application date is April 3, 1991, and the name of the invention is "electric chip"; and 3. The Republic of China The application date of the invention patent application number is May 17, 1991, and the name of the invention is 'pressure chip and its manufacturing method.' [Prior art] The finger of the ink was pressed to input the fingerprint. However, the above method cannot meet the needs of Vietnam's e-commerce, security systems, etc. A key technology known in the market for fingerprint reading method can use the paper attached to the paper and then use an optical scanner to scan the paper in the brain and then compare it with the fingerprint pattern in the database. The biggest disadvantage is that it ca n’t achieve the purpose of real-time processing. There are more and more real-time authentication requirements. ”For example: network authentication, security of tape electronic products, personal identity authentication of IC card, and the instant fingerprint reading device becomes biometric identification.

Page 8 200527665 V. Description of Invention (2). The traditional benefit number 4 is also high in accuracy. For various carrying purposes, it has been overcome, and the amount of capacitance has been exceeded. Please refer to the early literature. However, this way overcomes dry and clear electrostatic damage. Real-time fingerprint reading device 0 53, 2 2 8 and 4, 340 However, the volume is too large and the electronic optical fingerprinting items of the above-mentioned optical type using silicon semiconductors are taken from the chip to see the US patent. The sensor of the sensor "The patent has the following 1. Shen, but the thickness of the metal interlayer, one is the power of 2. The remaining is an optical method, please refer to the United States, No. 300, its development is quite It is mature, large and expensive, and it is not applicable and popularized. Chip-type fingerprint sensing devices have come into being at the historic moment. The test based on Shixi integrated circuit manufacturing process is the most direct and simple method, which is less than the number 4,290 The biggest problem of 052 and 4,353,056 chips is that they can't effectively measure the interference problem, and can't effectively prevent the previous newer technology to use the capacitive pressure-2 fingerprint detection method developed by M 4, and processing technology. Please refer to the above-mentioned patent application of the inventor of the present invention: the formula sensor and its manufacturing method. Missing = β solves the above problem. However, the patent application still has disadvantages. : 'Zi's upper electrode plate will bend down under pressure: Φ: / Move the upper electrode plate—a structure that bends and sinks down—and several metal plugs buried in it, a metal Compound two bumps and a cover layer. This composite floating structure is: 疋 t-Shiconi. Due to the degree of bending and sinking, the sensitivity of the entire floating structure is not high. The composition material of the complex β-type sweat structure in Yuku W is too complicated and easy to concentrate. The phenomenon of concentration of residual stress ’makes the characteristics of the entire sensor unstable.

200527665 V. Description of the invention (3) and the effect is not good. 3. Because the composition and material structure of the entire composite floating structure is susceptible to temperature rise or fall, the raw material is too much, and the complex effect is easy, making the sensor vulnerable to temperature rise or bimorph (Bimorph). Bad consequences. Noise is generated due to diversion. Therefore, how to provide a structure that can solve the above-mentioned measurement unit, Huiquan Tai'an & η w 1 J Jingzhi's capacitive pressure sensor Problem. SUMMARY OF THE INVENTION A structure and manufacturing method of the present invention A single material is thin, and the structure is achieved. The electrode plate, the layer, and a plurality of lower electrodes are electrically connected to the lower electrode capacitor. Its type summary includes a purpose to provide a capacitor structure. By this, the base layer has a gap, several etched metal bolts on the boards, and the gap is a dielectric layer cover gap. Electric pillars are formed in the first dielectric. The upper metal engraved window plug column is under the gold square, which is located at the first via hole and the first via hole of the overlying electrical layer connection and bonding layer. The fixing is a plug for fixing the lower bottom layer with a pressure to solve the problem of the invention, including a solid layer, a sealing plug and a lower electrode column. The floating fixed lower electrode plate is fixed below the middle part to the floating upper electrode. It is formed on the first capacitive sensing element junction. The substrate system has a fixed upper electrode electrode plate shape and a floating upper electrode plate, and the pressure sensing structure of the multiple dielectric layers of the one-round plate is almost a problem. Various pressure plates, / composite layers are suspended from the base plate in the bottom layer of the flat plate to float. The upper part of the upper gold peripheral measurement unit can be regarded as 0 force sensing unit floating on power, a protection is formed on the multi-layer, and floating between the fixed line board sensing. The first electrode plate and the peripheral part are embolized, and

Page 10 200527665 V. Description of the invention (4) Electrical connection to the upper metal plugs. The protective layer covers the edge portion of the first dielectric layer and the upper metal composite layer. A plurality of engraved window holes are penetrating ^ one " electrical layer and floating upper electrode plate. The etched window holes are located at the edges of the first dielectric portion and communicate with the gap. The sealing plugs are used to seal the etched window holes. The present invention also provides a method for manufacturing a capacitive pressure sensing element, which can effectively reduce the thickness of the composite marine structure, thereby improving the sensing effect. [Embodiment]

FIG. 1 shows a schematic diagram of a capacitive pressure sensing element 4 according to a preferred embodiment of the present invention. As shown in FIG. 1, the capacitive pressure sensor of this embodiment is a base layer 301, a fixed lower electrode plate 303A, and a floating J IJsO 〇 03V ^ 23 〇 09. Retaining layer 307, a plurality of etched window holes 308, and a thunderbolt bottom: a plurality of lower metal plugs 3202 and a related bottom electrode plate 3303A are formed in 30i. It is fixed on the base layer 301, and the metal plugs 302 of cobalt type a 忒 and the like. The fixed lower electrode plate 30 3A is composed of one, two, or two materials. Similarly, the floating upper electrode plate 3 0 3β is composed of a titanium oxide material, and it is suspended in the fixed lower electrode plate. Electrical 21 =, used to form a parallel plate sensing with the fixed lower electrode plate 3 03Α. Handle two R two: The gap 3J3C is located on the fixed lower electrode plate 3〇3Α and the floating upper electrode rq η. =. The first dielectric layer 304 covers the base layer 301, fixes the lower electrode, and moves the upper electrode plate 3 03β and the gap 3 03C. First dielectric layer 304 200527665 V. Description of the invention (5) --- = a middle portion 304A and a peripheral portion 304B. The peripheral part is 30 centimeters in shape and has a plurality of upper metal plug posts 305 electrically connected to the floating upper electrode plate 30B. The upper metal composite layer 306 is formed at a peripheral portion of the first dielectric layer 304, and is electrically connected to the upper metal plugs 305. The protective layer 3 0 7 is isolated from the first one; the peripheral portion 3 0 4B of the electrical layer 3 0 4 and the upper metal composite layer 3 06. The etched window holes 308 pass through the first dielectric layer 304 and the floating upper electrode plate 303B. The etched window holes 30 8 are located at the edge of the middle part of the first dielectric layer 30 4 and are connected to the gap 3 3C. The sealing plugs 309 are used to seal the etched window holes 308. The sealing plug 309 can be composed of a photoresist material, a metal material, a dielectric layer material such as silicon oxide material, silicon nitride material, silicon carbide and diamond-like carbon film, or a combination of the above materials. In order to further protect the parallel plate sensing capacitor 2 丨, such as dust, ^, abrasion and corrosion resistance, the material of the sealing plug 3 0 9 can also be used /

All upper surfaces of the outermost layer of the element. -Holding Figure 2E Capacitive pressure sensing element 2 0 can be used to sense the pressure change of a fluid (liquid or gas), it can also be used to sense tactile pressure 1 such as the tactile sensing of a robotic arm, especially this implementation In the example, it is applied to the fingerprint pattern to read force as a fingerprint sensor. When applied to a fingerprint sensor, the 'capacitive pressure sensing element 20 may further include a bump 3 丨 〇, which serves as a floating upper electrode. One of the plates 3 0 3 B is concentrated by a finger force. In this case, the upper metal composite layer 306 is further formed on the middle portion 304A of the first dielectric layer 304. The protective layer 307 further covers the middle portion 30 ″ of the first dielectric layer 304 and the metal composite layer 3 0 6 located on the middle portion 3 0 4A, so that the metal composite layer 30 located on the middle portion 3 0 4A 6 and the first dielectric layer 30 formed a bump

200527665 V. Description of the invention (6) 310 ° Figs. 2A to 2E show schematic cross-sectional views of a method for manufacturing a capacitive pressure sensor according to a preferred embodiment of the present invention. In particular, the manufacturing method and materials used in the present invention are fully compatible with commercial integrated circuit manufacturing processes, especially CMOS manufacturing processes. As shown in FIGS. 2A to 2E, a method for manufacturing a capacitive pressure sensor 20 of the present invention includes the following steps. First, as shown in the left half of Figure 2A, a sensor element initial structure 300 is provided. This sensor element initial structure 300 is completely based on commercial integrated circuit manufacturing processes and design guidelines. The only difference is that the final bond pad passivation opening has not yet been completed. It includes a base layer (silicon oxide) 301, a lower metal composite layer 303, a first dielectric layer (silicon oxide) 304, an upper metal composite layer 306, and a protective layer (silicon oxide). And silicon nitride composite layer) 307. A plurality of lower metal plugs 302 are formed in the base layer 301. The lower metal composite layer 303 is located on the base layer 301 and includes a first metal layer 303A, an alloy layer 303D, and a second metal layer 30 3B. The first metal layer 303A is in contact with the base layer 301. The alloy layer is located on the first metal layer 303A. The second metal layer 3 0 3 B is located on the alloy layer 30 3D. One input = the electric layer 304 covers the base layer 301 and the lower metal composite layer 303. The first part has a middle part 304A and a peripheral part 304B. Periphery belongs to erlang branch 30 / into a plurality of upper gold layers 30 7 which are electrically connected to the second metal layer 30 3B and are connected to the metal plug 30 5 on the net. Protection, said, the first dielectric layer 304 surrounding the peripheral portion 304B and the upper metal compound

Page 13 200527665 V. Description of the invention (7)-on layer 3 ◦ 6. Then, as shown in FIG. 2B, a part of the protective layer 307 is removed, so that the first dielectric layer 304 is exposed, and the metal composite layer 306 is located on the peripheral 9 portion 304B of the first dielectric layer 304. Not exposed. The right half of FIG. 2A and FIG. 2B show that the initial structure of the sensing element 3 〇 may further include a pad layer 3 丨], which is formed on the peripheral portion 3 0 4B of the first dielectric layer 3 04. The pad layer 311 is formed by the upper metal composite layer 306 and a protective layer 307 covering the upper metal composite layer 306. In the step of removing a part of the protective layer 3 07, a part of the protective layer 30 7 on the pad layer 3 1 丨 is removed to form a plurality of exposed pads 3 1 2. The pad 3 1 2 is a part that controls the input and output of the sensing element. The manufacturing method of the present invention can simultaneously define the pattern of FIG. 2B by using the steps of forming an indispensable pad. Next, as shown in FIG. 2C, a plurality of etched window holes 308 are formed on the exposed first dielectric layer. The etched window holes 3 08 pass through the first dielectric layer 3 04 and the second metal layer 3 0 3B to expose the alloy layer 3 3D, and the etched window holes 3 08 are located on the first dielectric layer. 3 04 the middle part of the edge of 304A. Then, as shown in FIG. 2D, the wafer that has completed the process of FIG. 2C is placed in an etching solution, so that the alloy layer 303D 'is etched with the etching solution from the etching window holes 308 to remove the alloy layer 303D, and The first metal layer 303A and the second metal layer 3 0 3 B are retained to form a fixed lower electrode plate 3 03A, a floating upper electrode plate 3 0 3 B, and a fixed lower electrode plate 3 0 3 a. One gap 3 0 3C from the floating upper electrode plate 3 03B. The floating upper electrode plate 303B is used to form a parallel plate sensing capacitor 21 with the fixed lower electrode plate 3 0 3 A. Next, as shown in FIG. 2E, a letter is formed around the etched window holes 308.

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200527665 V. Description of the invention (8) A mouth plug 30 9 is used to seal the etched window holes 308. As described above, the 'sensing element initial structure 300' may further include a bump 310 'which is located on the middle portion 3046 of the first dielectric layer 304. The bump 31o is not removed in the subsequent process, so as to serve as a force concentration point on the floating upper electrode plate 30b. In addition, the upper metal composite layer 306 is further formed on the middle portion 304A of the first dielectric layer 304, but the metal composite layer 306 located on the middle portion 304A is not electrically connected to the upper metal plugs 305. And in the step of removing a part of the protective layer 307, the protective layer 3 0 7 on the metal composite layer 3 06 located on the middle portion 304A is not removed, so that the metal compound on the middle portion 3 4 A is composited. A bump 310 is formed on the layer 3 0 6 and the protective layer 3 7. Produced in the commercial integrated circuit manufacturing process, the second metal layer 303B is composed of a titanium or titanium film, the first metal layer 3 0 3 A is composed of a titanium or titanium nitride film, and the alloy layer 30 3 D series is an aluminum alloy layer. This type of metal layer structure of 303A / 303D / 303B exists in various wafer manufacturing processes. The present invention uses this standard structure to design parallel plate capacitors. The same In the copper wire manufacturing process, the same concept can be used to select and remove copper materials. In this embodiment, the etching solution is a di-aluminum etching solution. The aluminum etching solution is a mixture of phosphoric acid, nitric acid, and acetic acid. It can quickly remove aluminum materials (> 1 micron / minute) at a suitable ratio and temperature. At the same time, this etching solution has excellent selectivity for titanium and titanium nitride, so it can complete the selective etching technique for removing aluminum and leaving titanium and titanium nitride. Seal = plug post 309 may be composed of a photoresist material, a metal material, a silicon oxide material, or a silicon nitride material.

Page 15 200527665 V. Description of the invention (9) The ingenious capacitive pressure sensing element can be completely controlled and stopped by the commercial integrated circuit manufacturing process, and the reading and processing of electricity should be easy. The integration is relatively below or next to the sensing frame to achieve a monohttnc design. The invention

The suspension structure of the measuring cell is characterized by a heart, a person, and a person, and it has a characteristic sense of ^, /, by the wounded brother, 1, the electrical layer 304, and the second metal layer 3 0 3 B ΓΛ :: the dielectric layer 3G4itf is The oxidized shredded material has a thickness of about 3 (nR, _, g ^ are different), and the second metal layer has a thickness of about 0 · 1 # m, so the double crystal structure formed by the two is approximately Layers, so the question caused by the double crystal structure can be ignored here. At the same time, the method of the present invention rit; HI-nr ^, the method of removing aluminum far titanium and titanium nitride can be combined into a solid lower electrode Plate 303A, floating upper electrode plate

The three-plate parallel plate capacitors have f-gap 3 03C real gaps, which can achieve the best pressure / capacitance variable sensitivity production. FIG. 3 shows the structure of the capacitive pressure sensing element of FIG. 2D: FIG. The composite floating structure 21 ^ window hole 308 and the bump 310 can be seen therein. It is called 1a and 4 layers 30. 7. At this point, you can find the structure and manufacturing process of the electrical pressure sensing element of the present invention. _ Manufacturing process, and because the gap between the two electrode plates of the force sensing element in February this year is quite, so even the pressure change is relatively small: two: sensitive detection, that is to say the surface of the sensing element X n 〇 " m below, can be greatly: = large: reduced to less than 100 fluid pressure sensing, the present invention is another-= the use as a traditional texture sensor, more detailed description will be used for the reference M 翏See above by the inventor

200527665 V. Description of the invention (10) Patent application "Pressure type fingerprint reading chip and its manufacturing method". FIG. 4 shows the three-dimensional intention of a fingerprint sensor using the structure of the capacitive pressure sensing element of the present invention. Please refer to FIG. 4 ′ The fingerprint sensor 2 of the present invention includes a plurality of capacitive pressure sensing elements 20 arranged in a two-dimensional (2-D) array manner and fabricated on a silicon substrate 200. The structure of each capacitive pressure sensing element 20 is mainly a flat-panel sensing capacitor 2 including a fixed lower electrode plate 303A at the bottom (Fig. 0 and the composite floating structure 21 &. The surroundings of the composite floating structure 21a are fixed. In the #substrate 200 'in the middle of the upper and lower electrode plates, a line gap of 303C (FIG. 1), and at the center of the upper electrode plate, at least one bump 23 (FIG. K31〇) is made as a finger when the force is applied. The stress concentration point increases the displacement of the composite floating structure 21a (large capacitance change) to increase sensitivity. In each capacitive pressure sensing element 20, one is designed below each sensing capacitor 21 A reference capacitor (not shown) is connected to it, and is equipped with a signal reading unit 22 next to the sensing capacitor 21 so that the detected signal is processed and output immediately. Figure 5 shows the capacitor to which the present invention is applied. Block diagram of a fingerprint sensor with the structure of a pressure sensing element. As shown in FIG. 5, the fingerprint sensor of the present invention includes a capacitive pressure sensing element array 201, of which a specific capacitive pressure Sensing element 2 0 is transmitted through a column of decoders 2 0 2 Pass the specific word line 2 〇 2 a to select, and then by the row decoder 2 0 3 through a plurality of line control lines 2 1 2, a continuous double sampler (Correlated Double Sampling (CDS) 204 and the specific bit line 2 0 3a, read the voltage signal of the specific capacitive pressure sensing element 20. The function of cds can remove noise and get a better signal-to-noise ratio. The analog signal of the read voltage is finally amplified by an amplifier 2 0 5 , And then by an analog / digital conversion

Page 17 200527665 V. Description of the invention (11) Change = 2 0 6 Convert the analog signal into a digital signal output. The above actions are all controlled by an avoidance control and interface circuit 20, and the logic control and interface circuit 210 is connected to a terminal system through a high-density flash memory interface. The above-mentioned components 202, 202a, 203, 203a, and 204 to 210 may be referred to as peripheral circuits 2 1 1. For a more detailed description, please refer to the aforementioned patent application "Pressure type fingerprint reading chip and its manufacturing method" by the inventor of the present case. = 6 shows the three-dimensional display of the fingerprint sensor in Figure 4 when reading a fingerprint ^. . When finger 1 contacts the pressure-type capacitive pressure fingerprint sensor 2, the irregular shape of the finger 1 surface (R i dg e) 1 1 will exert a force on the capacitor ^ The capacitance of the part of the hand-sensing element array 2 01 Type pressure sensing element 20, and a capacitance corresponding to the ripple peak 丨 丨 is left on the pressure fingerprint sensor 2 and the valley 1 1 a can be obtained by reading the shape of the capacitance curve 丨 丨 & The shape of the ripple peak η is further described in FIG. 7. The original fingerprint Θ 7 shows one of the fingerprint sensors in Figure 4 when reading the fingerprint. Taxi: As shown in FIG. 7, the parallel plate of the capacitive pressure sensing element 20 is shown in the figure + meaning that the composite foreign moving structure 2la and the fixed lower electrode 21b (" 1 in Figure i, and 21 J in each figure) In the middle of the two electrode plates is an air gap 24, and the group: the central formation-bump 23 is used as a concentrated point of force to increase the displacement of the structure 2U electrode plate. When you try to keep up with the up / variable force sensing array, there are only 8A; the fingerprint peaks are 1 1 contact (some sensing elements are covered by fingers :: left :), and feel from the finger i Pressure, this pressure creates V: valley] of the composite floating structure 2 ia 吝 where your child depends on the pressure of the sensor you taught to), build: 1 & produce a displacement (the amount of displacement depends on the location Then change the capacitance value between two parallel plates.

200527665 V. Description of the invention (12) Take, it can reflect the number of capacitive pressure sensing elements 20 in this array, which are changed by the fingerprint peak 11 contact, and then the shape distribution of fingerprint peak η is constructed. 1 1 a. This sensing principle fully reflects the force distribution of the fingerprint of the hand, and the wet and dry fingers will not interfere with the fingerprint reading. At the same time, the composite floating structure 21a is connected to the ground potential, and the static electricity of the fingers is directly conducted to the ground potential like the lightning rod principle, which will not damage the circuit at the bottom. The biggest feature of the manufacturing of the capacitive pressure fingerprint sensor of the present invention is that it can completely adopt the commercial sub-micron metal-connected integrated circuit manufacturing process, especially the complementary metal-oxide-semiconductor manufacturing process. For the sake of simplicity, only how to use a commercial integrated circuit manufacturing process to complete the structural design and material properties of a single parallel plate sensing capacitor 21 is provided. As for other circuit designs and dreams as a conventional technique, we will not repeat them here. For the sensing principle of the capacitive pressure sensing element and the structure of the trigger switch, please refer to the related patent mentioned above: "Capacitive pressure micro-sensing element and its manufacturing method and signal reading method". With the above-mentioned structure and method, the present invention can reduce the thickness of the composite floating structure 2 1 a 'simplify the constituent materials of the composite floating structure 21 1 a, so it can improve the sensitivity of the entire floating structure and avoid stress concentration. Therefore, the characteristics of the entire sensor are very stable and the effect is very good, and there is no noise caused by the bimorph effect. The specific embodiments proposed in the detailed description of the preferred embodiments are for convenience only, to clarify the technical content of the present invention, rather than to limit the present invention to the above embodiments in a narrow sense, without exceeding the spirit of the present invention and the following applications The circumstances surrounding patents and the implementation of various changes are within the scope of the present invention.

Page 19 200527665 Brief Description of Drawings Figure 1 shows a schematic cross-sectional view of the structure of a capacitive pressure sensing element according to a preferred embodiment of the present invention. 2A to 2E are schematic cross-sectional views showing a method for manufacturing a capacitive pressure sensor according to a preferred embodiment of the present invention. Fig. 3 shows a schematic top view of the structure of the capacitive pressure sensing element of Fig. 2D. FIG. 4 shows a three-dimensional schematic diagram of a fingerprint sensor using the structure of the capacitive pressure sensing element of the present invention. FIG. 5 shows a block diagram of a fingerprint sensor using the structure of the capacitive pressure sensing element of the present invention. FIG. 6 is a schematic perspective view of the fingerprint sensor of FIG. 4 when reading a fingerprint. FIG. 7 is a schematic diagram showing the principle of the fingerprint sensor of FIG. 4 when reading a fingerprint. [Description of Symbols of Components] S 1 ~ Logic signal 1 ~ Finger 2 ~ Capacitive pressure fingerprint sensor 1 1 ~ Wave peak 2 0 ~ Capacitive pressure sensing element 2 1 ~ Parallel plate sensing capacitor 2 la ~ Composite Floating structure 2 1 b ~ fixed lower electrode

Page 20 200527665 Brief description of the drawing 2 2 ~ Signal reading unit 2 3 ~ Bump 24 ~ Gap 2 0 0 ~ Broken substrate 2 0 1 ~ Capacitive pressure sensing element array 2 0 2 ~ 歹 J decoder 2 0 2 a ~ word line 2 0 3 ~ row decoder 2 0 3a ~ bit line 2 0 4 ~ continuous subsampler 2 0 5 ~ amplifier 2 0 6 ~ analog / digital converter 2 0 8 ~ power saving control Circuit 2 1 0 ~ logic control and interface circuit 21 1 ~ peripheral circuit 2 1 2 ~ row control line 3 0 0 ~ sensor element initial structure 301 ~ base layer 302 ~ lower metal plug post 303 ~ lower metal composite layer 303A ~ fixed Lower electrode plate (first metal layer) 3 0 3B ~ Floating upper electrode plate (second metal layer) 303C ~ gap 303D ~ alloy layer

Page 21 200527665 Schematic description

3 0 4 ~ first dielectric layer 3 0 4A ~ middle part 3 0 4B ~ peripheral part 305 ~ upper metal plug post 306 ~ upper metal composite layer 3 0 7 ~ protective layer 3 0 8 ~ etched window hole 3 0 9 ~ Sealing plugs 3 1 0 ~ Bump 3 1 1 ~ Solder pad layer 3 1 2 ~ Pad

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Claims (1)

200527665 VI. Scope of patent application 1. A structure of a capacitive pressure sensing element, comprising: a base layer in which a plurality of lower metal plugs are formed; a lower electrode plate fixed on the base layer and electrically connected To the lower metal plugs; a floating upper electrode plate suspended above the fixed lower electrode plate to form a parallel plate sensing capacitor with the fixed lower electrode plate; a gap between the fixed lower electrode plate and Between the floating upper electrode plates; a first dielectric layer covering the base layer, the fixed lower electrode plate, the floating upper electrode plate, and the gap; the first dielectric layer has a middle portion and a peripheral portion A plurality of upper metal plugs electrically connected to the floating upper electrode plate are formed in the peripheral portion; an upper metal composite layer is formed on the peripheral portion of the first dielectric layer and is electrically connected to the upper portions; A metal plug; a protective layer covering the peripheral portion of the first dielectric layer and the upper metal composite layer; a plurality of etched window holes penetrating the first dielectric layer and the floating upper electrode Plate, the etched window holes are located at the edge of the middle portion of the first dielectric layer and communicate with the gap; and a plug plug is used to seal the etched window holes. 2. The structure of the capacitive pressure sensing element described in item 1 of the patent application scope further includes a bump, which serves as a stress concentration point on the floating upper electrode plate. 3. Capacitive pressure sensing element as described in item 2 of the scope of patent application 200527665 Six-junction and inter-junction structure are applied for patent scope, ~~ structure, where the upper metal composite layer is further formed on the first dielectric screen part ^, and the protective layer further covers the first dielectric layer. The middle part two: the middle part, on which the upper metal composite layer is 'used'; the upper metal composite layer of the middle knife and the first dielectric layer constitute the convex structure 4 :: Zhongshen II The capacitive pressure sensing element described in page 11 of the Zhonghai Haihai plug plug system is composed of a photoresist material, a material, an oxidation / material, or ~ nitriding dream material. The capacitive pressure sensing element described in item 1 of the above-mentioned method, wherein the fixed lower electrode plate is made of a titanium metal material, which is a type of capacitive pressure. 60% 丨 Fetching 0: The manufacturing method of the flying force sensor element, including the following steps, providing an initial structure of the sensor element in the middle part, a base layer in which a complex-lower metal composite layer is formed, and the element : A first metal layer on the first metal layer of the base; and a second gold-first dielectric layer covering the base I dielectric layer having a middle portion and an electrical connection to the base The second metal layer is an upper metal composite layer, which forms an upper layer and is electrically connected to the upper metal and a protective layer. The first metal layer includes: a plurality of lower metal plugs; on the base layer, the lower layer. The metal composite bottom layer is in contact; an alloy layer, a metal layer, is located on the alloy layer; the bottom layer and the lower metal composite layer, a peripheral portion, a plurality of upper metal plugs in the peripheral portion; The peripheral plug column; and the peripheral portion of the plant power layer and the Μ Page 24 200527665 VI. Patent application scope on the metal composite layer; remove a part of the protective layer, so that the first dielectric layer is exposed, and the upper metal located on the peripheral portion of the first dielectric layer The composite layer is not exposed; a plurality of etched window holes are formed on the exposed first dielectric layer, the I-etched window holes penetrate the first dielectric layer and the second metal layer to expose the alloy layer, and The etched window holes are located at the edges of the middle portion of the first dielectric layer; and the alloy layer is etched with an etching solution from the etched window holes to remove the alloy layer and retain the first metal layer And the second metal layer to form a fixed lower electrode plate, a floating upper electrode plate, and a gap between the fixed lower electrode plate and the floating upper electrode plate, respectively, the floating upper electrode plate is used to communicate with the The lower electrode plate is fixed to form a parallel plate sensing capacitor; a mouth plug is formed around the etched window holes to seal the etched window holes. 8. The method for manufacturing a capacitive pressure sensing element as described in item 7 of the scope of the patent application, wherein the initial structure of the sensing element further includes a bump located on the middle portion of the first dielectric layer, and the bump The block is not removed to serve as a stress concentration point on the floating upper electrode plate. 9. The method for manufacturing a capacitive pressure sensing element as described in item 8 of the scope of patent application, wherein the upper metal composite layer is further formed on the middle portion of the first dielectric layer, but is located on the middle portion. The upper metal composite layer is not electrically connected to the upper metal plugs, and in the step of removing a part of the protective layer, the protection on the upper metal composite layer is located on the middle portion. Page 25 200527665 —— VI. Scope of patent application —— — ^: not to be removed ’, so that the bit and the protective layer form the bump. Manufacturing method on the hard mouth layer: 0: Go to each method of the capacitive dust sensor described in item 7 of the Ui Lee range. The initial structure of the sensor further includes: 俨: a cushion layer formed on the first layer. On the peripheral portion of the dielectric layer, the second layer: the one-third of the step of the metal composite layer and the protective layer covering the bright metal layer covering the upper metal composite layer is exposed in this step. Pads. λ "A part of the thin shell is removed 'to form a plurality of capacitive pressure sensing elements described in item 7 of the manufacturing application patent range, wherein the second metal layer is composed of a titanium nitride material. The manufacturer of the capacitive pressure sensing element described in item 7 of the scope of the patent application, wherein the first metal layer is composed of a titanium metal material. The manufacture of the soil is as described in item 7 of the scope of the patent application. Capacitance force sensing element: Fang: To 'where the alloy layer is a Ming alloy layer, and = you are an aluminum etching solution. 4 cold liquid manufacturing 1 side 4 · Faru Shen 专 special μ range 12th It is made of the capacitive pressure and measurement unit described in Item 1. The aluminum etching solution is a mixed structure of phosphoric acid, nitric acid and acetic acid. The sealing and plugging column is composed of a photoresist material, a gas / fossilized material, or a nitrided material. Page 26