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WO2009111669A2 - Techniques de dopage sans masque pour cellules solaires - Google Patents

Techniques de dopage sans masque pour cellules solaires Download PDF

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Publication number
WO2009111669A2
WO2009111669A2 PCT/US2009/036239 US2009036239W WO2009111669A2 WO 2009111669 A2 WO2009111669 A2 WO 2009111669A2 US 2009036239 W US2009036239 W US 2009036239W WO 2009111669 A2 WO2009111669 A2 WO 2009111669A2
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WO
WIPO (PCT)
Prior art keywords
substrate
ion beam
ion
exposed
system comprises
Prior art date
Application number
PCT/US2009/036239
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English (en)
Other versions
WO2009111669A3 (fr
Inventor
Atul Gupta
Nicholas P.T. Bateman
Paul J. Murphy
Anthony Renau
Charles Carlson
Original Assignee
Varian Semiconductor Equipment Associates
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from US12/200,117 external-priority patent/US20090317937A1/en
Application filed by Varian Semiconductor Equipment Associates filed Critical Varian Semiconductor Equipment Associates
Publication of WO2009111669A2 publication Critical patent/WO2009111669A2/fr
Publication of WO2009111669A3 publication Critical patent/WO2009111669A3/fr

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Classifications

    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10F—INORGANIC SEMICONDUCTOR DEVICES SENSITIVE TO INFRARED RADIATION, LIGHT, ELECTROMAGNETIC RADIATION OF SHORTER WAVELENGTH OR CORPUSCULAR RADIATION
    • H10F71/00—Manufacture or treatment of devices covered by this subclass
    • H10F71/121—The active layers comprising only Group IV materials
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E10/00—Energy generation through renewable energy sources
    • Y02E10/50—Photovoltaic [PV] energy
    • Y02E10/547—Monocrystalline silicon PV cells
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

Definitions

  • Solar cells are typically manufactured using the same processes used for other semiconductor devices, often using silicon as the substrate material.
  • a semiconductor solar cell is a simple device having an in-built electric field that separates the charge carriers generated through the absorption of photons in the semiconductor material. This electric-field is typically created through the formation of a p-n junction (diode) which is created by differential doping of the semiconductor material. Doping a part of the semiconductor substrate (e.g. surface region) with impurities of opposite polarity forms a p-n junction that may be used as a photovoltaic device converting light into electricity.
  • Figure 1 shows a cross section of a representative substrate 100, comprising a solar cell. Photons 10 enter the solar cell 100 through the top surface 105, as signified by the arrows. These photons pass through an anti- reflective coating 110, designed to maximize the number of photons that penetrate the substrate 100 and minimize those that are reflected away from the substrate.
  • the substrate 100 is formed so as to have a p-n junction 120.
  • This junction is shown as being substantially parallel to the top surface 105 of the substrate 100 although there are other implementations where the junction may not be parallel to the surface.
  • the solar cell is fabricated such that the photons enter the substrate through the n-doped region, also known as the emitter 130.
  • the photons with sufficient energy (above the bandgap of the semiconductor) are able to promote an electron within the semiconductor material's valence band to the conduction band. Associated with this free electron is a corresponding positively charged hole in the valence band. Sn order to generate a photocurrent that can drive an external load, these electron hole (e-h) pairs need to be separated.
  • any e-h pairs that are generated in the depletion region of the p-n junction get separated, as are any other minority carriers that diffuse to the depletion region of the device. Since a majority of the incident photons are absorbed in near surface regions of the device, the minority carriers generated in the emitter need to diffuse across the depth of the emitter to reach the depletion region and get swept across to the other side. Thus to maximize the collection of photo-generated current and minimize the chances of carrier recombination in the emitter, it is preferable to have the emitter region 130 be very shallow. Some photons pass through the emitter region 130 and enter the base 140.
  • contacts 150 typically metallic, are placed on the outer surface of the emitter region and the base. Since the base does not receive the photons directly, typically its contact 150b is placed along the entire outer surface. In contrast, the outer surface of the emitter region receives photons and therefore cannot be completely covered with contacts. However, if the electrons have to travel great distances to the contact, the series resistance of the cell increases, which lowers the power output. In an attempt to balance these two considerations; the distance that the free electrons must travel to the contact, and the amount of exposed emitter surface 160; most applications use contacts 150a that are in the form of fingers.
  • Figure 2 shows a top view of the solar cell of Figure 1.
  • the contacts are typically formed so as to be relatively thin, while extending the width of the solar cell. In this way, free electrons need not travel great distances, but much of the outer surface of the emitter is exposed to the photons.
  • Typical contact fingers 150a on the front side of the wafer are 0.3 mm with an accuracy of +/- 0.1mm. These fingers 150a are typically spaced between 1-5 mm apart from one another. While these dimensions are typical, other dimensions are possible and contemplated herein.
  • FIG. 3 shows a cross section of this enhanced solar cell.
  • the cell is as described above in connection with Figure 1, but includes heavily n-doped contact regions 170.
  • These heavily doped contact regions 170 correspond to the areas where the metallic fingers 150a wil! be affixed to the substrate 100.
  • the introduction of these heavily doped contact regions 170 allows much better contact between the substrate 100 and the metallic fingers 150a and significantly lowers the series resistance of the cell.
  • This pattern of including heavily doped regions on the surface of the substrate is commonly referred to as selective emitter design.
  • a selective emitter design for a solar cell also has the advantage of higher efficiency cells due to reduced minority carrier losses through recombination due to lower dopant/impurity dose in the exposed regions of the emitter layer.
  • the higher doping under the contact regions provides a field that repels the minority carriers generated in the emitter and pushes them towards th
  • This design can be extended by having narrow highly doped lines between the metallization lines. Such lines could be orthogonal to the metallization lines. These highly doped, low resistance lines allow charge to flow across the emitter to the contacts, and reduce the series resistance of the emitter.
  • Such structures are typically made using traditional lithography (on hard masks) and thermal diffusion.
  • An alternative is to use implantation in conjunction with a traditional lithographic mask, which can then be removed easily before dopant activation.
  • Yet another alternative is to use a stencil mask in the implanter to define the highly doped areas for the contacts. All of these techniques utilize a fixed masking layer (either directly on the substrate or in the beamline).
  • a improved, lower cost method of producing solar cells utilizing selective emitter design is disclosed.
  • the contact regions are created on the substrate without the use of lithography or masks.
  • the method utilizes ion implantation technology, and the relatively low accuracy requirements of the contact regions to reduce the process steps needed to produce a solar cell.
  • the current of the ion beam is selectively modified to create the highly doped contact regions.
  • the ion beam is focused, either through the use of an aperture or via adjustments to the beam line components to create the necessary doping profile.
  • the wafer scan rate is modified to create the desired ion implantation pattern. These techniques can also be used in other ion implanter applications.
  • Figure 1 shows a cross section of a solar cell of the prior art
  • Figure 2 shows a top view of the solar cell of Figure 1;
  • Figure 3 shows a cross section of a solar cell using selective emitter design;
  • Figure 4 shows a top view of the solar cell of Figure 3;
  • Figure 5 shows a coordinate system used with the present disclosure
  • Figure 6 shows a traditional ion implantation system
  • Figure 7 shows a graph of substrate holder speed as a function of substrate position
  • Figure 8 shows a graph of scanner frequency as a function of substrate position
  • Figure 9 shows amoduled extraction electrode power supply for use with the ion implanter of Figure 6
  • Figure 10a shows a set of plates in the open position for use with the ion implanter of Figure 6;
  • Figure 10b shows a set of plates in the closed position for use with the ion implanter of Figure 6
  • Figure 11a shows an aperture in the open position for use with the ion implanter of Figure 6;
  • Figure lib shows an aperture in the closed position for use with the ion implanter of Figure 6;
  • Figure 12a shows a representative scanning waveform used to create nonuniform dosing;
  • Figure 12b shows a representative substrate creating using the scanning waveform of Figure 12a; and Figure 13 shows an embodiment wherein the scanning waveform is used to adjust a focusing element.
  • FIG. 4 shows a top view of the solar eel! manufactured using the methods of the present disclosure.
  • the solar cell is formed on a semiconductor substrate 100.
  • the substrate can be any convenient size, including but not limited to circular, rectangular, or square. Although not a requirement, it is preferable that the width of the substrate 100 be less than the width of the ion beam used to implant ions in the substrate 100. However, no such limitation exists with respect to the orthogonal direction of the substrate. In other words, a substrate 100 can be arbitrarily long, and can be in the shape of roll of solar cell material. Typically, the substrates for solar cells are very thin, often on the order of 300 microns thick or less.
  • the solar cell has an n-doped emitter region and a p-doped base.
  • the substrate is typically p-doped and forms the base, while ion implantation is used to create the emitter region.
  • a block diagram of a representative ion implanter 600 is shown in Figure 6.
  • An ion source 610 generates ions of a desired species, such as phosphorus or boron.
  • a set of electrodes (not shown) is typically used to attract the ions from the ion source. By using an electrical potential of opposite polarity to the ions of interest, the electrodes draw the ions from the ion source, and the ions accelerate through the electrode. These attracted ions are then formed into a beam, which then passes through a source filter 620.
  • the source filter is preferably located near the ion source.
  • the ions within the beam are accelerated/decelerated in column 630 to the desired energy level.
  • a mass analyzer magnet 640 having an aperture 645, is used to remove unwanted components from the ion beam, resulting in an ion beam 650 having the desired energy and mass characteristics passing through resolving aperture 645.
  • the ion beam 650 is a spot beam.
  • the ion beam passes through a scanner 660, preferably an electrostatic scanner, which deflects the ion beam 650 to produce a scanned beam 655 wherein the individual beamlets 657 have trajectories which diverge from scan source 665.
  • the scanner 660 comprises separated scan plates in communication with a scan generator.
  • the scan generator creates a scan lakeage waveform, such as a sine, sawtooth or triangle waveform having amplitude and frequency components, which is applied to the scan plates.
  • the scanning waveform is typically very close to being a triangle wave (constant slope), so as to uniformly expose the scanned beam at every position of the substrate for nearly the same amount of time. Deviations from the triangle are used to make the beam uniform.
  • the resultant electric field causes the ion beam to diverge as shown in Figure 6.
  • An angle corrector 670 is adapted to deflect the divergent ion beamlets 657 into a set of beamlets having substantially parallel trajectories.
  • the angle corrector 670 comprises a magnet coil and magnetic pole pieces that are spaced apart to form a gap, through which the ion beamlets pass.
  • the coil is energized so as to create a magnetic field within the gap, which deflects the ion beamlets in accordance with the strength and direction of the applied magnetic field.
  • the magnetic field is adjusted by varying the current through the magnet coii.
  • other structures, such as parallelizing lenses can also be utilized to perform this function.
  • the scanned beam is targeted toward the substrate, such as the solar cell to be processed.
  • the scanned beam typically has a height (Y dimension) that is much smaller than its width (X dimension). This height is much smaller than the substrate, thus at any particular time, only a portion of the substrate is exposed to the ton beam.
  • the solar cell is attached to a substrate holder.
  • the substrate holder provides a plurality of degrees of movement. For example, the substrate holder can be moved in the direction orthogonal to the scanned beam.
  • a sample coordinate system in shown in Figure 5. Assume the beam is in the XZ plane. This beam can be a ribbon beam, or a scanned spot beam.
  • the substrate holder can move in the Y direction. By doing so, the entire surface of the substrate 100 can be exposed to the ion beam, assuming that the substrate 100 has a smaller width than the ion beam (in the X dimension).
  • emitter region will be used to denote the lightly doped portions of the emitter region.
  • contact region will be used to denote the heavily doped portions of the emitter region.
  • emitter region refers to any n-doped portion of the substrate.
  • the lightly doped exposed emitter region 160 is created by traditional implantation techniques.
  • a low current ion beam can be used to implant the entire surface of the substrate 100 at a uniform doping level.
  • the substrate 100 is positioned between the two ends of the beam, and the substrate holder moves the substrate 100 in the Y direction until the entire substrate has been exposed to the beam.
  • the amount of doping that results from the implantation is proportional to the current of the ion beam, and the dwell time, which is the amount of time that a particular area is exposed to the ion beam. In other words, greater dwell time and/or higher current will result in heavier doping of the irradiated area.
  • the substrate can be exposed to the required low dosage to create the exposed emitter region 160.
  • the beam is normally scanned along the X direction.
  • the substrate holder then moves the substrate in the Y direction. Using this combination of movements, the entire substrate is exposed.
  • the same result can be obtained using a fixed spot beam and moving the substrate holder in both the X and Y directions, until the entire surface is exposed.
  • the resulting ion beam has a width (in the X dimension) much greater than its height (in the Y dimension).
  • aspect ratio is defined as width/height
  • the resultant ion beam has an aspect ratio greater than 2, preferably greater than 10.
  • the highly doped contact regions 170 are implanted during a second implantation step.
  • the movement of the substrate holder is modified so as to create longer dwell times at the regions corresponding to the contacts for the metallic fingers.
  • the substrate holder is moved more quickly in the Y direction over those portions of the substrate that are not to be further implanted (i.e. the exposed emitter regions 160).
  • the speed of the substrate holder in the Y direction slows. This slower speed is maintained while the ion beam is over the contact region.
  • the translational speed of the substrate holder increases so as to quickly pass over the subsequent lightly doped exposed emitter region 160. This process is repeated until the entire substrate has been implanted.
  • Figure 7 shows a graph slowing the relative speed of the substrate holder in the Y direction, as a function of the position of the substrate. Note that when the exposed emitter region 160 is exposed to the ion beam, the speed is increased. When the contact region 170 is exposed to the ion beam, the speed is slowed to increase the doping dose.
  • the speed may be varied continuously between 2 levels to have continuously graded dopant profiles with regions of high doping (for contacts) with lightly doped regions in between. Such a velocity profile could be sinusoidal or triangular.
  • a similar technique can be used to move the substrate holder at a variable speed in the Y direction, based on the 5 position on the substrate. If the substrate holder also moves in the X direction to scan across the wafer, the holder can vary the speed in the X direction to achieve the same results described above. In other words, the substrate holder moves quickly in the X direction while exposing lightly doped exposed emitter regions of the substrate, but slows when exposing the contact regions. 0 Alternatively, the speeds of the substrate holder can be varied in both the X and Y directions if desired.
  • the scanner 660 can be controlled to create a similar result. Assume, in a scanned spot beam implementation, for example, that the substrate holder moves in the Y direction, and that the scanner 660 5 causes the spot beam to move in the X direction. By varying the frequency of the sawtooth wave used to control the scanner, the rate that the spot beam traverses the substrate can be modified. In one scenario, the frequency of the scanner control signal is increased as the ion beam passes over the exposed emitter region, and is slowed when the ion is exposed to the contact region. O Figure 8 shows a graph representing this embodiment. In this way, the dweli time of the exposed emitter region is less than that of the contact region.
  • the waveform of the scanner control signal is modified so that the spot beam is positioned so as not to strike the substrate when passing through the exposed emitter region, and only scans when in the 5 contact region. Combining the modification to the scanner input waveform with an alteration to the speed of the substrate holder in the Y direction can also be performed.
  • the speed of the substrate holder in the Y direction is such that the required low dosage of ions is implanted in the exposed emitter region.
  • the beam must pass over the substrate at all locations; it is only the dwell time at the various locations that is modified.
  • the speed of the substrate holder in the Y direction can be increased significantly over the exposed emitter region 160, as this area has already been doped.
  • the beam can be positioned so as not to hit the substrate in the exposed emitter region 160, and only be exposed to the substrate while in the contact region 170.
  • One such technique to create the desired implantation pattern is to vary the ion beam current based on the region of the substrate. This can be accomplished in a number of ways.
  • the ion beam is adjusted by varying the voltage used at the extraction electrodes.
  • Figure 9 shows a simplified ion implantation system, with only the ion source 600 and the substrate holder 710 shown for clarity.
  • the ion source 600 is used to generate the ion beam 730 to be implanted on the substrate 100.
  • These ions are attracted through the extraction slit 700 of the ion source by one or more sets of extraction electrodes 720. The electrical potential of these electrodes 720 determines the resulting ion beam current.
  • the electrical potential of the electrodes 720 is very similar to that of the chamber walls of the ion source 600, the flow of ions out of the ion source 600 will be minimal, as there is no attraction to the electrode. Conversely, if the electrical potential is dramatically different than the chamber walls of the ion source, the ions will be strongly attracted to the electrodes 720. This will result in an ion beam 730 of much higher current.
  • the electrical potential of the electrodes 720 By varying the electrical potential of the electrodes 720 based on the position of the substrate with respect to the ion beam, the desired implantation pattern can be attained.
  • Figure 9 shows the use of a pulsed extraction power supply 740 that is activated whenever the contact region 170 of the substrate 100 is in a position where the ion beam will irradiate it. The pulse is then deactivated whenever the ion beam exposes the exposed emitter region 160.
  • Other components of the ion implantation system can be similarly controlled so as to vary the ion beam current. There are numerous components that can be adjusted in the beam line. For example, a focusing lens element can be pulsed periodically to focus and defocus the beam as the substrate is being scanned to create alternating regions of high and low dopant doses. Such focusing elements may be magnetic (i.e. quadrupole lenses) or electrostatic (i.e. Einze! lenses).
  • the defocusing or focusing of the beam changes the amount of beam that is transmitted into the process chamber (and irradiates the substrate), thus varying the effective beam current incident on the workpiece.
  • two passes can be used, if desired.
  • other beamline components that control the transmission of beam through the implanter may be changed. Such components include Acceleration/Deceleration voltages, Magnet settings, and the like.
  • apertures are used to modify the beam width.
  • two plates 800,810 shown in Figure 10a, are used to create a variable width aperture 820.
  • the plates lie on opposite sides of the ion beam 730, and move toward one another to close the aperture 820.
  • the plates 800, 810 are separated, as shown in Figure 10a, allowing the beam to pass through.
  • the plates 800, 810 move toward one another, so as to minimize or eliminate the aperture 820, as shown in Figure 10b.
  • the aperture is used to create the implant pattern.
  • a device such as that shown in Figures 11a and lib, is used to create the alternating pattern.
  • the device may consist of a rotating barrel or cylinder with a through slit, or aperture, such as along the diameter.
  • the device is rotated about an axis normal to the direction of travel of the ion beam.
  • the beam can only irradiate the substrate when the slit, or aperture, in the rotating device becomes aligned with the beam direction.
  • Figure 11a shows the orientation of the aperture when the beam is able to pass through the device.
  • Figure lib shows an orientation where the beam is unable to irradiate the substrate.
  • the relative positions of the apertures on the opposing sides of the cylinder, as well as the width of the opposing apertures determine the duty cycle of the implant pattern. For example, wider apertures enable the passage of the beam over a wider range of angular rotation, while narrow apertures permit the passage of the beam over a smaller range of angular rotation.
  • the speed at which the device rotates determines the frequency at which the ion beam irradiates the substrate. While a cylinder is described above, other shaped devices can also be used, as long as the rotation of the device causes the apertures to align such that the ion beam can periodically pass through the device.
  • the system To create the desired implantation patterns, it is important for the system to understand the position of the substrate relative to the ion beam. In other words, the system must be aware that the contact region is being exposed in order to supply the proper amount of ions. This information can be determined in a number of ways.
  • the system can rely strictly on timing. In other words, the synchronization of the substrate holder to the other components of the system is accomplished based on the time elapsed since the start of the operation.
  • a more accurate approach is to include patterns at the edge of the substrate.
  • the system can determine the position of the substrate with respect to the ion beam based on these patterns, and operate accordingly. This method is preferably in that the system does not need any information concerning the implant pattern prior to starting the operation.
  • the patterns on the substrate supply the necessary information for the system to correctly implant the substrate. Such patterns and marking systems are well known to those skilled in the art.
  • the dose can be varied as a function of the substrate location that is being exposed to the ion beam. It is also possible to vary the beam transmission characteristics based on the scan position of the beam (i.e. in the X direction).
  • a spot beam is used.
  • the ion beam passes through an electrostatic scanner 660, which deflects the ion beam 650 to produce a scanned beam 655.
  • the scan generator creates a scan voltage waveform, such as a sine, sawtooth or triangle waveform having amplitude and frequency components, which is applied to the scan plates.
  • the scanning waveform is typically very close to being a triangle wave (constant slope), so as to uniformly expose the scanned beam at every position of the substrate for nearly the same amount of time.
  • the scanner waveform can be utilized in a variety of ways to vary the dose implanted on the substrate.
  • the typically triangular waveform is replaced with an alternative waveform.
  • modifications to the scan waveform can produce similar effects in the horizontal direction (i.e. along the X axis).
  • Figure 12a shows a scanning waveform that could be used to generate three areas of high dosing on a substrate in the X direction.
  • the slope of the waveform indicates the speed at which the scanner moves the ion beam across the substrate in the X direction. Those portions of the waveform with very small slopes will create higher doses than those portions with steeper slopes.
  • Figure 12b shows the resulting substrate dosing, with three areas of high dosing, corresponding to the three portions of the waveform with small slopes, while the remainder of the substrate is lightly dosed.
  • the scanner waveform can be used to vary the adjustable beamfine components.
  • a threshold detector can be used to enable or disable an adjustable beamline component.
  • Figure 13 shows a threshold detector 900 having one or threshold detection points. The detector receives the scanning waveform from the scanning waveform generator 910 and varies its output such that the adjustable beamline component is enabled when the amplitude of the scanning waveform is between certain values, and is disabled at other times.
  • Such an embodiment can be used to create vertical strips of high dosing on the substrate. By using a plurality of thresholds, it is possible to create patterns similar to that shown in Figure 12b.
  • the threshold detector circuit may enable its output its output if the amplitude of the scanning waveform is between .15V and .3V, between .45V and .60V, or between .75V and .9V. Such a configuration would yield three vertical stripes of higher dosing. Obviously, other embodiments are possible and within the scope of the disclosure.
  • the workpiece support is moved at a constant rate so that time can be used to estimate the position of the substrate relative to the ion beam.
  • a counter or timer is then used, in conjunction with the scanning waveform and the above described threshold detector, to create patterns of dosing which vary as a function of both horizontal and vertical position.
  • patterns on the substrate are used to determine the vertical position of the substrate with respect to the ion beam. This information is then used in combination with the scanning waveform to create an output used to control the adjustable beamline component.

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  • Photovoltaic Devices (AREA)

Abstract

La présente invention concerne un procédé amélioré et à moindre coût permettant de produire des cellules solaires à l’aide de la technologie de l’émetteur sélectif. Les régions de contact sont créées sur le substrat sans utilisation de la lithographie ou d’un masque. Le procédé utilise la technologie de l’implantation ionique, et des conditions de précision relativement faible des régions de contact pour réduire les étapes de procédé nécessaires pour produire une cellule solaire. Dans certains modes de réalisation, le courant du faisceau d’ions est sélectivement modifié pour créer les régions de contact fortement dopées. Dans d’autres modes de réalisation, le faisceau d’ions est concentré, soit par l’utilisation d’une ouverture, soit par le biais de réglages des composants de la ligne de faisceau pour créer le profil de dopage nécessaire. Dans d’autres modes de réalisation encore, le taux de balayage de la tranche est modifié pour créer le motif d’implantation ionique souhaité.
PCT/US2009/036239 2008-03-05 2009-03-05 Techniques de dopage sans masque pour cellules solaires WO2009111669A2 (fr)

Applications Claiming Priority (6)

Application Number Priority Date Filing Date Title
US3387308P 2008-03-05 2008-03-05
US61/033,873 2008-03-05
US7427808P 2008-06-20 2008-06-20
US61/074,278 2008-06-20
US12/200,117 2008-08-28
US12/200,117 US20090317937A1 (en) 2008-06-20 2008-08-28 Maskless Doping Technique for Solar Cells

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WO2009111669A2 true WO2009111669A2 (fr) 2009-09-11
WO2009111669A3 WO2009111669A3 (fr) 2009-12-17

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US8697552B2 (en) 2009-06-23 2014-04-15 Intevac, Inc. Method for ion implant using grid assembly
US8697553B2 (en) 2008-06-11 2014-04-15 Intevac, Inc Solar cell fabrication with faceting and ion implantation
WO2015044341A1 (fr) * 2013-09-27 2015-04-02 International Solar Energy Research Center Konstanz E.V. Procédé de fabrication d'une structure de contact de cellule photovoltaïque et cellule photovoltaïque correspondante
US9318332B2 (en) 2012-12-19 2016-04-19 Intevac, Inc. Grid for plasma ion implant
US9324598B2 (en) 2011-11-08 2016-04-26 Intevac, Inc. Substrate processing system and method

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Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8697553B2 (en) 2008-06-11 2014-04-15 Intevac, Inc Solar cell fabrication with faceting and ion implantation
US8871619B2 (en) 2008-06-11 2014-10-28 Intevac, Inc. Application specific implant system and method for use in solar cell fabrications
US8697552B2 (en) 2009-06-23 2014-04-15 Intevac, Inc. Method for ion implant using grid assembly
US8749053B2 (en) 2009-06-23 2014-06-10 Intevac, Inc. Plasma grid implant system for use in solar cell fabrications
US8997688B2 (en) 2009-06-23 2015-04-07 Intevac, Inc. Ion implant system having grid assembly
US9303314B2 (en) 2009-06-23 2016-04-05 Intevac, Inc. Ion implant system having grid assembly
US9741894B2 (en) 2009-06-23 2017-08-22 Intevac, Inc. Ion implant system having grid assembly
US9324598B2 (en) 2011-11-08 2016-04-26 Intevac, Inc. Substrate processing system and method
US9875922B2 (en) 2011-11-08 2018-01-23 Intevac, Inc. Substrate processing system and method
US9318332B2 (en) 2012-12-19 2016-04-19 Intevac, Inc. Grid for plasma ion implant
US9583661B2 (en) 2012-12-19 2017-02-28 Intevac, Inc. Grid for plasma ion implant
WO2015044341A1 (fr) * 2013-09-27 2015-04-02 International Solar Energy Research Center Konstanz E.V. Procédé de fabrication d'une structure de contact de cellule photovoltaïque et cellule photovoltaïque correspondante

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