TWI296858B - Back-contact solar cells and methods for fabrication - Google Patents

Description

1296858 • V. Abstract of Chinese Invention: A method of manufacturing a full-coverage (EWT) back contact type solar cell and a battery fabricated in such a manner. Some methods provide a higher concentration of dopant at the conduction path compared to the average concentration of dopants on the front or back surface, which increases the efficiency provided. There are a number of ways to provide selective doping of the pores to form a feed channel using the transfer. Other methods are used to spin-coated glass substrates containing dopants. • VI. Abstracts of English Inventions: VII. Designation of Representative Representatives: (1) The representative representative of the case is: (3Α). (2) A brief description of the symbol of the representative figure: 12· · · · Plane wafer 34 - paste 34 · · · · Boron - diffusion source paste _ VIII, if there is a chemical formula in this case, please reveal The chemical formula that best shows the characteristics of the invention. IX. Description of the invention: [Technical field to which the invention pertains] The related application is a "contact fabrication of Emitter Wrap" -Through Back

Contact Silicon Solar Cells"", by Peter Hacke and James Μ Gee, in the United States Public Service 3 1296858 - Application for Legal Agent Matter Number (U.S. Utility Patent

Application Attorney Docket No.) 31474-1005-UT, and the name "Buried-Contact Solar Cells With Self-Doping Contacts" n, James J. M. Gee and Peter Hacke, found in the U.S. Patent Application Attorney Docket No. (#), which is filed with the application of the present invention. This, and its detailed project is included here for reference. This application is filed in the US Patent Provisional Application No. 60/542,390 under the name "Fabrication of Back-Contact • Silicon s〇iar Cells f", filed on February 5, 2004. Japanese, Japanese, and U.S. Patent Provisional Application Serial No. 60/542, 454, the use of self-mixed contacts to manufacture a buried contact solar cell (pr〇cess f〇r φ Fabrication of Buried-Contact) Cells Using Self-Doping

Contacts) ’’, the priority rights filed on February 5, 2004, and the detailed items are included here for reference. BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a method of fabricating a back contact type solar cell, and more particularly to an emitter full envelope (EWT) solar cell having a conductive via, and a solar cell fabricated therefrom. [Prior Art] 4 1296858 Please note that the following discussion refers to some of the authors and the year's publications. The discussion of these publications here is intended to provide a more complete background and not to be interpreted as a prior art for the purposes of patent approval. Nowadays, it is widely used to make a miscellaneous battery (10) with a p/n junction formed in the front table © (surface of the contact wire) _, which generates electron flow when the battery is light. A common battery design has a set of electrical contacts on its front side and a second set of electrical contacts on the back side of the solar cell. In a typical photovoltaic module, these solar cells are electrically connected to each other in a (four) manner to increase the voltage. This-connected f-based method uses a tin-light method to weld a conduction belt from the front side of a solar cell to the rear side of an adjacent solar cell. Compared with a conventional solar cell, the f-side contact solar cell has advantages.帛 € € _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ The first: __ face contact type battery polarity connection ^ taste taste # ‘ is also relatively cheap, this is because two pool electricity two to two photovoltaic modules and solar power back contact her = completed, (four) Jing coffee saves the effect. ^ Shouting - the advantage is that it can provide a more uniform appearance with a better aesthetic effect of 1296858. Aesthetic considerations are important for certain applications, such as building-total photovoltaic systems and automotive roof covers for automobiles. Figure 1 provides an overview of a typical back contact solar cell. The enamel substrate 12 in the figure may be of an η-conductive type or a p-conductive type. In some designs, one of the densely blended shots, such as pH blended shot 18 or n++ blended shot 16, may be omitted. Or in other designs, the densely blended shots 16, 18 may be in direct contact with one another on the back surface. The back-surface passivation layer 14 φ helps to reduce the loss of the photo-generated carrier on the back surface and helps reduce the electrical losses caused by the current splitting on the undoped surface between the metal contacts 20. There are some ways to cut solar cells for moon-to-surface contact. These methods include metal wrap (MWA), full metal cladding (MWT), full body cladding (EWT), and backside-junction structures. MWA and MWT have current collecting metal grids on their front surfaces. These grids are individually formed as a back contact type battery by being wound around the side or by completely covering the holes to the back side surface. The unique part of the EWT battery is that it has no metal covering on the front side compared to the just-powered #cell, which means that no light that is incident on the battery is blocked, resulting in higher efficiency. The EWT battery wraps the current collecting junction ("projector") from the front surface to the back surface, passing through the conductive channels that have been blended in the Shihua wafer. , the emitter, and the semiconductor device are associated with a densely blended region. Such a guiding passage can be produced by, for example, drilling a hole on a stone substrate by means of a laser, and then forming an emitter inside the hole while forming an emitter on the front and rear surfaces. 6 1296858 • The side-connected remuneration has a negative polarity and positive polarity current collecting junction at the time of the solar power. Because most of the light is absorbed - also caused by the dawn of the carrier - near the front surface, the back side - junction battery requires a very high material quality so that the carrier has enough _ diffused from the front surface to the back The current collecting junctions on the surface and the back surface are together. In contrast, EWT batteries retain the current collecting junction on the front surface, which is the advantage of high current collection efficiency. The EWT battery publication is disclosed in US Patent No. 5, 468, 652, Method of Making A Back Contacted Solar Cell, and the patent belongs to James Μ Gee. Its full content is included here. The design of various backside contact cells has also been discussed in many technical publications. • In addition to US Patent 5, Preparation, 652, and two other US patents by Gee, the co-inventor, the publication reveals module combinations and stacks using back-contact solar cells. Method; it is US Patent No. 5,951,786, Laminated Photovoltaic Modules Using Back-Contact

Solar Cells), and US Patent No. 5, 972, 732, Method of Monolithic Module Assembly. The methods and related matters disclosed in the two patents may be used with the present disclosure as disclosed herein, and are hereby incorporated by reference in its entirety. US Patent No. 6, 384, 316, solar cell and its manufacturing process 7 乂ar Cell and Process of Manufacturing the Same), a cloth is not another kind of ★ face contact battery design, but the side veins, the holes or The distance between the two is relatively long, and there are metal contacts on the front surface to help conduct current to reach the back surface, and the holes therein are in line with the metal back. In some cases, an EWT cell with a channel that diffuses with a gas dopant will exhibit a high series resistance associated with this pass. Seen in [jM·Ji, Μ·Ε·Buck, W. 舒·Schubert, and ρ·Α·Basso, the progress of the whole body of the solar cell, published in the 12th European Photovoltaic Solar Energy Research Conference, Amsterdam, The Netherlands, April 1994 (J·Jie Gee, Μ·Ε· Buck, W·L Schubert, and PABasore, Process on the Emitter Wrap-Through Silicon Solar Cell, 12th European Photovoltaic Solar Energy Conference, Amsterdam, The Netherlands, April 1994)], J. M., D. D. Smith, S. E. Jarrett, MD Boddi, and JC Gimino, etc.: Back Contact Crystallization - Solar Energy Battery and Module (Gee JM, Smith DD, Garret SE, BodeMD, Jimeno JC: Back-Contact

Crystalline-Silicon Solar Cells and Modules). The NCPV Project Review Conference, September 8-11, 1998, in the NCPV Program Review Meeting (8-11 September 1998, Denver, CO), proposed in the meeting: One way to deal with this problem is Metallic materials, such as metallized materials, fill the channels. However, this method adds 1296858 to the manufacturing process, which is obviously complicated and therefore expensive. Another method is to increase the density of the channel in order to obtain an acceptable (four) junction resistance. _, this also adds to the complexity of the cost of a better way, the hole part of the blending is thicker than the surface part, as long as the process can be kept simple and low. At least some of the data suggest that the common gas diffusion method, such as the use of liquid phase diffusion of liquid chlorinite fine (10) 13), results in less diffusion within the pores than on horizontal or planar surfaces. It may be because the dopant gas permeates through the hole and is not as efficient as passing through the exposed surface. _, other information found that the hole is conductive and consistent, and its interior is doped and similar to the exposed surface. [D·D·Smith, J. Μ.Ji, Μ·D·Body, and J.C. Gimino, et al., Circuit Simulation Model for Full Body Wrapped Solar Cells, Yuji, Christine Electronic Engineers Association Journal of Electronic Devices, Vol. 46, 1993 (1999), (DD Smith, JM Gee, MD Bode, JC Jimeno, Circuit modeling of the emitter-wrap-through solar cell, IEEE • Trans· on Electron Devices, Vol · 46, 1993 (1999))]. The key issue with any lunar contact type 1% battery is the development of a low cost manufacturing process that isolates the negative and positive grid from the junction. Such technical problems include patterning of the doped layer (if any), passivation of the surface between the negative and positive contact regions, and application of the negative and positive conductive contacts, and the like. SUMMARY OF THE INVENTION The present invention is a method for fabricating a (four) fully-coated (10) T) solar cell, the method comprising the steps of: providing a semiconductor wafer having a front surface and a back surface and _ extending from the front surface to the back a hole in the surface; applying a first dopant diffusion source to the back surface to a pattern pattern containing the back surface holes, applying a second dopant diffusion source on the back surface to the back surface The pattern of the holes is diffused from the first dopant diffusion source and the second dopant diffusion source into the semiconductor wafer. The semiconductor wafer preferably comprises 11, the first dopant source preferably comprises a structure, and the first species source preferably comprises. Preferably, the method further comprises applying a first dopant diffusion source comprising scales to the pattern of the front surface comprising the front surface apertures. At least a portion of the holes in the step of applying the first dopant diffusion source are preferably filled by the first dopant source. Preferably, the edge method further comprises the steps of: engraving the four half-body _15 with an acidic solution after the diffusion step, applying a force σ-type to the passivated dielectric layer to > a front surface of the circle; and a metal grille of the first conductive type is applied to the pattern of at least a portion of the pattern of the first-valve diffusion method, and the metal grid of the second type is applied Applied to the back surface comprising at least a portion of the pattern pattern of the second dopant diffusion source pattern pattern. The invention is also another method for fabricating a solar cell, the method consisting of: providing a semiconductor crystal with a tree surface and a back surface to 1296858

And a plurality of holes extending from the front surface to the rear surface; applying a diffusion barrier to the rear surface does not include the back surface pores __式#; cleaning the wafer; diffusing the first dopant into the human Wafer; the crystal is engraved to at least partially remove the surface oxide; and the first-shaped metal thumb is applied to the rear surface including the back surface hole __ pattern, and the second conductivity type metal The grid is applied with a smooth surface by the diffusion layer and the first conductivity type of the metal grid. Preferably, the semiconductor wafer is = P-type, and the first dopant is preferably phosphorus. The metal grid of the first type preferably contains silver, and the second type is preferably _ Preferably, the method comprises the inclusion of a correction-term surface, and __(4) is followed by applying a passivation layer to at least a portion of the surface of the dielectric layer _p-type material; wherein the resistance caused by applying the first dopant source is Between squares (1) / (8); and where the first, / 〇 fox

The steps of the thumb include the pattern of the transfer grid pattern and the contrast of the Hongpee and the conductivity type of the first dopant: the impurity is preferably the second type of the trace type: Expand the ship inside the customs. It is best to combine the present invention with the present invention and to make an EWT solar cell: a semi-conductor j296858 and a hole extending from the front surface to the rear surface; the first spin-coating glass (s〇 G) diffusing the barrier layer to the back surface; applying a resist to the pattern without the back surface hole/same pattern; surname the wafer to remove the first spin-on glass (S〇G) without pattern a resist-covered portion; removing the resist from the wafer, diffusing the first dopant into the wafer; etching the wafer to at least remove the remaining first spin-on glass (SOG); And adding a metal conductive yoke of the first conductivity type to the pattern of the back surface including the hole of the back surface, and applying the metal grid of the second conductivity type to the pattern of the back surface containing the pattern of the resist pattern . Preferably, the semiconductor wafer comprises Shi Xi, the first dopant preferably contains phosphorus, and the first spin-on glass (s〇G) is preferably applied by spin coating or spraying. Furnace densification and other methods. The first spin-on glass (s〇G) preferably contains a second dopant that is opposite to the conductivity pattern of the first dopant. The present invention is also another method of fabricating an EWT solar cell, the method consisting of providing a semiconductor wafer having a front surface and a back surface and a plurality of holes extending from the surface of the crucible to the back surface; The first spin-on glass (S0G) of the dopant to the back surface; applying a resist to the pattern pattern that does not include the back surface holes; etching the wafer to remove the first square-coated glass (SOG) a portion that is not covered by the patterned anti-surplus; removes the anti-surname agent from the wafer; applies a second spin coating comprising a second type of dopant having a conductivity pattern opposite the first dopant Glass (S〇g) to the back surface; baking the wafer to diffuse the first dopant and the second dopant into the wafer; 12 1296858

The wafer is left to remove at least the remaining first and second net weight-spinning glass (SOG); and the first-conducting type of metal grid is applied to the county surface including the back surface hole pattern, and The two-lead metal peach is applied to the pattern of the back surface containing the pattern of the resist pattern. Preferably, the method further comprises the step of: displacing the third spin-on glass (9) onto the hard-surfaced surface, the third spin-on glass (9) G) preferably comprising a lower than the spin-on glass (SOG) in the crucible. The second dopant of concentration. In this method, it is preferable to carry out the cultivating, which comprises arranging the plurality of wafers to be substantially parallel and proceeding from the front surface to the rear surface, so that the second spin-on glass (the (10) second from the rear surface of the first wafer is obtained. The dopant is diffused to the adjacent front surface of the immediately adjacent second wafer. The present invention further provides a leg solar cell fabricated by any of the methods. The primary object of the present invention is to provide a cost-effective process for the manufacture of a simple cost-effective process. The higher efficiency of the rider (10) τ) solar cells.

The present invention further provides a method of increasing the number of dopants in the conduction path, thereby providing a lower series resistance to the bile solar cell.曰本电明 another - the goal is to provide a kind of _ to the diffusion barrier manufacturing process, and it is best to spread the barrier layer as a kind of doping __, to mention the back side - contact junction nature. The hybrid invention, in turn, aims to provide dispersed but simultaneous diffusion for two different dopants, η-dopant and _. The main advantage of the present invention is that it provides an improved and simpler method of producing EWT solar power 13 1296858 cells at a lower cost. Yet another advantage of the present invention is that in the method provided by the method, the conductive channel and the phase line on the back surface and the wire can be arbitrarily escapable, using n+-dopant, preferably _, to The remaining remaining surface portions are more densely blended. Other objects, advantages, and novelty of the present invention, as well as other applicability

The scope and the like, in part, will be presented in the following detailed description in conjunction with the accompanying drawings, and in part will become apparent to those skilled in the learned. The _ target money point may be realized and achieved by applying the means and combinations thereof. [Embodiment]

U.S. discloses that the method of manufacturing a back contact type solar cell and the process of providing a relatively simple, more reliable and more economical process and process. It will be understood that although there are some individual parties that cannot be extracted, the skill in the related art may be combined or changed into two or more methods, thus providing another additional manufacturing method. Time 卩 will be understood = although the drawings and process sequence examples describe the manufacture of the back contact type solar energy 2 'there are some examples of the caps that make the other back contacts ^ such as dew, job, or back Side-junction solar cells. Specifically, the use of "transfer diffusion barrier layer and dopant diffusion barrier layer and spin-on glass diffusion barrier layer" and "using spin-on glass as 14 1296858 as diffusion barrier layer and dopant source" The method below can be applied directly to any back contact solar cell, including but not limited to kMWT, MWA and backside-junction solar cells. It will be readily confirmed by one of the techniques in the related art that certain modifications will be made depending on the difference in battery structure, but such methods are generally still applicable to back contact type solar cells. In some embodiments, the method of the present invention provides a cell in a densely packed (possibly P++ or n++) manner within the channel body, that is, in the channel, approximately the cylindrical sidewall and associated The inner grid or front surface dopant lines are included; if compared to the remaining horizontal battery surface, more particularly the remaining front or top surface, it is also blended with impurities, but in smaller amounts. For example, in a P-type germanium wafer, the conductive vias will be more densely n++-blended than most of the front surface. Preferably, in some embodiments the n++-doped grid line includes a channel opening formed on the front surface that corresponds to the back surface ruler, and optionally optionally provides an n++-blended grid line It intersects at channel φ at right angles, while the remaining area of the front surface is blended with n+-. This means that the current resistance to the channel and through the channel is relatively small, rather than using a single η+ emitter for both surfaces and channels. This results in an increase in efficiency and allows the hole density to be reduced without the need for metallization of the channel. In each of the methods described hereinafter, the wafer can be of a typical thickness, typically greater than 280 to 300 microns, such as the commonly used 330 micron wafer. Alternatively, in the process sequence of the present invention, the wafer can be greatly thinned, for example, less than about 15 1296858 • 280 microns, preferably less than about 20 microns, and even less than about 100 microns. The secret is turned into a process sequence that does not contain metal, such as the alloy "long", the entire surface of the wafer is saturated or mostly, which is usually used to provide - back field (10)) at the back surface Recombination loss ("passivation"). Because of the inconsistency in the coefficient of thermal expansion between the wafer and the back field (the thermal expansion coefficient of aluminum is more than 1〇 greater than that of 矽), the strain is typically used, typically using wafer thicknesses greater than 28 μm. In this article, the commonly owned U.S. Patent Application Serial No. 10/880,190, entitled, The Fully Wrapped Back-Connected Solar Cell on a Thin Wafer Wafer, was presented to Mr. Ji and Mr. Schmidt. On June 29, 2004 (entitled "Emitter

Wrap-Through Back Contact Solar Cells On Thin Silicon Wafers" to Gee and Schmit, and filed on June 29, 2004) ^ The applicants are hereby incorporated by reference. The wafer can be any area, such as 25 square centimeters or 1 square centimeter (1 centimeter χ 1 centimeter), or # may be a little larger, such as 156 square centimeters or 225 square centimeters currently in use. In a first step of the various embodiments described below, the holes are used to form the conductive channels and are introduced into the planar germanium wafer 12 having the front and back surfaces, as shown in Figures 2A and 2B. The holes connect the front surface of the wafer to the back surface, which is preferably formed by laser drilling, but may be formed by other processes, such as dry engraving, wet engraving, mechanical drilling, or Water jet machining. In the case of laser drilling, the laser used is preferably at a wavelength of 16 1296858 with sufficient discrimination or intensity to facilitate the introduction of the shortest time, for example from about 5 milliseconds to 5 milliseconds per hole. One possibility is to use a Q-switched titanium yttrium aluminum garnet laser (Nd: YAGLaser). The time used for the introduction of wafers for the lucky/mother-to-L-hole is also proportionally shortened. The diameter of the passage holes may be from about 25 to 125 microns, preferably from about 30 to 6 microns. In the case where a thin crystal is used, for example, a wafer thickness of a micron or less, the diameter of the via hole is approximately greater than or equal to the thickness of the wafer. The channel hole per unit surface area _ is based on the degree of resistance of the material. In some cases, the current is transmitted through the hole through the hole to reach the acceptable resistance loss of the material Φ. This can be determined empirically or theoretically; the hole density of the channel in the method of the present invention may be reduced by reducing the resistance, e.g., by ohms/square (Q/sq). Typically, the channel hole density is 1 hole per square millimeter to 2 square millimeters, but it may also be the lower density, for example, 1 hole per 2 to about 4 square millimeters. After the introduction of the holes, for example by laser drilling, followed by the usual alkaline etching steps, the part is designed to minimize the irregularities caused by the introduction of holes. Any commonly used method can be used, for example, at about 80 ° C to a large _. (10) A temperature of «% by weight of sodium hydroxide or potassium hydroxide which removes a surface of about 10 microns. Use of a thin-diffusion source paste In an embodiment of the invention, a diffused diffused material source is used, with a screened diffuser source as a priority, and a dopant is provided inside the void. Although the source of the 'V mouth and the moon is 17 1296858 is known, as taught in US Patent No. 4,478,879, the material is never in the Lin EWT battery structure, or used in the hole. A higher concentration of η-dopant is produced in the immediate vicinity thereof, thereby providing a reduced series resistance. Applicants have inadvertently discovered that a source of diffused diffusion, such as a phosphorus-diffusion source, is selectively applied to the pore region, and the grid lines including the pore portions, resulting in a greatly increased concentration of dopants and Reduced resistance. The representative process sequence for the transfer of the diffused material source for the manufacture of the back contact type EWT battery is as follows. 1. Laser drilling 2. Alkaline etching 3. Transfer the phosphorus-diffusion source onto the front surface and dry it. 4. Transfer the phosphorus-diffusion source onto the back surface and dry it. The boron-diffusion source is transferred onto the back surface and dried. 6. The dopant is diffused into the crucible in a high temperature furnace. 7. Hydrogen fluoride etching (both surfaces are phosgenated) 8. Plasma treatment is applied to the front surface. Chemical vapor deposition (PECVD) 9. Plasma-assisted chemical vapor deposition (PECVD) on the back surface 10. Transfer and dry the silver metal paste for the negative polarity grid. 11. Transfer the silver to the positive polarity grid: aluminum metal Paste and dry it 12. The clothing (four) sequence of the baking contact surface is generally described in 3D, which illustrates that the manufacturing process of this method also reveals other advantages. The cross-sectional view of Fig. 2A shows that the wafer 12 has been drilled and etched to create a hole 3, which is the above steps 丨 and 2. Figure 2B is a top plan view of a portion of wafer 12 showing a plurality of holes spaced apart in a sequence. Figure 3A is a cross-sectional view of wafer 12 after the phosphor-diffusion paste has been transferred to the front and back surfaces in a patterned pattern such that each row of holes 3 is covered by a row of pastes 32. The boron-diffusion source paste 34 is transferred onto the rear surface so as to form a grid region where the pastes 32 and 34 form a mutual cross. Thus, FIG. 3A shows the wafer formed through the above steps 3 to 5. These pastes are converted to diffusion source oxides after drying and baking. The figure shows the wafer after the dopant has diffused southward. The boron diffusion layer 40 is generated by being diffused into the crucible below the diffusion oxide. Phosphorus is diffused into the crucible below the phosphorus-diffusion oxide to produce a phosphorus-diffusion layer. The diffusion layer is densely doped because phosphorus is easily diffused and has a higher surface concentration than boron. The entire area inside the hole 30 is densely blended, even if the doped paste does not fill the hole G, the g is the inner surface of the hole is from the front side and the back side of the hole doping paste 32 The dopant is full and saturated. The densely blended surface 36 is advantageous because it reduces the contact resistance with the subsequent grid applied to the back surface, reduces the resistance loss when conducting through the holes 3, and reduces conduction to the front surface. Loss of resistance at the time of the hole 30. As shown further in Figure 3B, the lightly blended layer 38 is produced on the surface of the crucible exposed on the front and back surfaces. The phosphorus of the lightly blended phosphorus diffusion layer 38 is derived from the T-doped material in the doped paste 32 which is evaporated from the barrier-diffusion oxide during the 19-high dispersion, and also evaporates from the sound-diffusing oxide, but The vapor pressure is low and the main vermiculite 4 is diffused into the exposed surface. It is advantageous to have a lightly diffused layer 38 on the front surface, which provides a combination of the best current collection and the lowest surface recombination. It is also advantageous to lightly mix the blended phosphorus diffusion layer 38 on the back surface because the scales have a passivation effect on the back surface, and the place where the scale diffusion layer is in contact with the butterfly diffusion layer is less likely to cause electrical Diversion. Therefore, this process sequence produces a battery structure with high efficiency potential. After the diffusion of the high temperature dopant, a side step (hydrogen fluoride enrichment) using an aqueous solution of hydrofluoric acid (HF acid) is usually used. Any suitable acid name can be used, for example, 10% hydrofluoric acid. Any common method of applying the secret coffee may be used, including immersing the wafer in a solution containing hydrofluoric acid. With sufficient hydrofluoric acid segment _ so that the surface and the back surface are water-staining, which can be determined by the sheeting effect of the hydrofluoric acid aqueous solution when the wafer is removed from the solution. The surface of the bare original stone that may be produced by the surname may need to be purified by deposition of a dielectric layer. The nitrided silicon (SiN) deposited by plasma-assisted chemical vapor deposition (PECVD) is used for solar cell fabrication as a surface passivation. a well-known technique, either 'thermal growth with a layer of SiO2 (Si2), or with other dielectric materials such as oxidizing), bismuth (Ti〇2), five 1296858 KTa2G5) and the like are deposited using a non-finished cylinder, such as a transfer method, a spray method, and a Wei-Yi-Yi, to purify the shaft surface. - Generally, as discussed below, the diffusion-barrier oxide does not need to be completely removed. If it has the nature of the town: the tree layer has a good interface and low recombination, and silver·Sau or other P-type joints can be baked and the low-resistance contact with the p-type substrate. In a certain embodiment, in the screen printing The last material frit is used in the point material. Leaving the diffusion-barrier oxide in place allows for at least one processing step, PEcvj) deposition step on the back surface. After surface passivation, a negative-polar grid connection is then applied. Point and positive-polar grid joints. Any common common method of grid metal application may be used, for example, silver paste is screen-transferred as a negative-polar grid joint, while silver: aluminum paste is transferred. Printing as a positive-polar grid contact. The paste can be made by re-combining a particle type of silver or silver: aluminum, and as appropriate, a liquid formulation may additionally contain a binder, a solvent, and in the present technology. Substances that are known and commonly used in the field, so that they can be used as a paste for screen transfer. It is also possible and worthwhile to utilize a paste formulation that contains components that can decompose nitrides (see M. Hilary et al.) Self-blending silver paste baking optimization to achieve high fill factor on tantalum solar cells with 100 ohm/square emitters" 'The 29th International Electro-Mechanical Engineers Association Optoelectronics Expert Workshop, New Orleans, Louisiana, May 2, 2, incorporated herein by reference (seeM. Hilali, et al., ffOptimization of self-doping Ag paste 21 1296858 firing to achieve high fill factors On screen-printed silicon solar cells with a 100 ohm/sq. emitter% 29th IEEE Photovoltaic Specialists Conf·, New Orleans, LA, May 2002, incorporated here by reference)), such as glass frit. The wafer is then baked to metallize the grid contacts. 3C shows a completed solar cell with a silver-aluminum paste as a negative-polar grid and a silver paste as a positive-polar grid, and a silver-negative negative-φ polar grid junction 42 after baking and Silver: Aluminum positive-polar grid contact 44. The layer of tantalum nitride deposited by PECVD, which can be optionally applied, is not clearly shown. Please note that all figures, including here and elsewhere in this application, the size and size of the holes and enamel substrates, the spacing and relative size of the different component structures, the thickness of the different layers, and other dimensions are not scaled. , but a display of the outline mode for illustration and easy identification. As shown in Fig. 3D, in a consistent example of a product obtained by screen printing a diffused material source, special (9) is a fill-source source is a desired pattern pattern 36 plus a channel hole 30 '(4) An increase in dopant concentration and a corresponding decrease in the encapsulation resistance are provided, such as a 'negative-polarity grid. The pattern pattern can be used with the sound. It is also the county _ sound ___ material fine front surface on the back surface. On the back surface, the pattern pattern 36 is then partially replaced (10) by the metallized grid 44, in the overlaying action of the pattern. It is also possible, for example, on the front surface to provide a grid of increased density of the inclusions 22 1296858 on the χ-axis and the broad axis, which is derived from the pattern pattern of the screen 璘 diffusion source, causing the channel to appear on every -x - The intersection of the grid line and the 7_ grid line, thus providing better current collection capability. There is also a diffusion effect of a small amount of domain impurities, such as chlorinated _(_3), and the subsequent oxidized side presses it to provide surface passivation on the front and back surfaces. Preferably, the process step is turned off prior to the hydrogen __ step to remove the diffusion source oxide. In the case of another phase-implementation, the step of the WE-diffusion chlorination (P0C13) is as described above, and the step of transferring the phosphorus-diffusion source onto the front surface is omitted. In each such implementation, the amount of impurities caused in the pore structure is higher than the average scale doping amount on the surface of the former money. A similar process sequence can be used for the fabrication of other back contact cell structures. In this-embodiment, especially on the back surface, 'Q(1) redundancy is not required, if the diffusion-source oxide and silk plate are low-re-combination interface, and if silver and silver: noisy check# Low-connected __ oxygen recording baking, for example, using the shaft of Chengchi and the silver paste of the job. The extension of the diffusion barrier diffusion barrier of Marriage 7 is used in another example of Ben Maoming, which uses a diffusion barrier layer to prevent or limit the diffusion of fjn+, such as chlorination (10) (3) Those who are known to add gas enthalpy dopants. It is best to transfer the diffusion barrier layer to 23 1296858, Niang. The straight-on-printing layer can be applied simply and directly to the patterning step. Suitable materials for the diffusion barrier layer can be purchased, 4 such as *, Feiluo (Kefran Ohio) supply of titanium dioxide anti-reflective layer of transfer paste, as a layer of enamel material, and as a All of these materials provide a good barrier work in the diffusion side of phosphorus. Although some (four) systems, such as transfer gods, have not previously been described as providing a diffusion layer. The composition of the glass provides the added benefit of dispersing under the barrier material, helping to passivate the surface and reduce the fine resistance of the positive contact. The diffusion barrier material is applied to the desired yoke, for example, by the _ plate transfer method, although there are also 曰代方村(四)上', for example, ink jet printing, masking method, etc., assuming that such a method can produce a tape _ diffusion barrier material. In the present example and the following examples, the dopant diffusion is preferably carried out using a gaseous source such as chlorination (p?cl3) to perform scale diffusion. Other sources of diffusion sources, such as _ source or spray diffuser sources, may also be used. The oxide from the complete side is usually removed from the hydrogen as it may cause reliability problems in the package. Therefore, its preferred order is to remove the scale oxides and diffusion-block oxides from the scale diffusion layer by hydrofluorination. The surface of the bare rock may need to be passivated by the sinking of a dielectric layer. In the solar cell fabrication (10) surface passivation process, the nitride nitride (10) deposited by the plasma assisted chemical vapor deposition (PECVD) is a well-known technique. Alternatively, it may be grown by the thermal growth of the layer of the oxidized hair (10) 2) or by other dielectric materials such as cerium oxide (Si〇2), titanium dioxide (Τι〇2), and pentoxide (10) (6). For example, a transfer method, a spray coating method, or a chemical vapor deposition method is used to form surface passivation. In general, as discussed below, the diffusion-shielding oxide does not need to be completely removed. (IV) has the following properties: good interface with the outer layer and low recombination, as well as silver·· Lu or other p-type The contact material can be used for the whole material to be cultured and the low-resistance pick-up of the type-type Shixi substrate is used in the joint material of the plant-transfer. Leaving the diffusion-barrier oxide in place allows for at least a processing step, a PEOT) deposition step on the back surface. The representative process sequence for producing a fine contact cell using the transferred diffusion layer is as follows. The step of providing a diffusion __ oxygen recording removal step (as discussed above) "double surface hydrofluoric acid residue, hydration" step, and diffusing the -P capping oxide to form a surface passivation layer Replacement, for example, for surface blunt lion nitrogen cuts. Fine, domain-like, if the diffusion, the oxidized fresh ^ (four) 妓 good interface, the job - the hetero-oxides do not have to be completely removed and replaced by PECVD nitride, so you can omit a step. 1·Laser drilling 2·Intestinal|Insect engraving 25 1296858 ' 3. Transfer diffusion barrier layer 4. Dry and bake 5· Surname and clean the wafer 6. Use phosphine chloride (P0C13) (30 Up to 60 ohms/square) 7. Hydrogen fluoride etching (both surfaces are phosgenated) 8. Pre-surface application of plasma-assisted chemical vapor deposition (PECVD) of tantalum nitride 9. Post-surface application of plasma-assisted chemical vapor deposition (10) CVD) 矽 矽 1 〇 · Negative grid transfer silver metal paste 11 · Positive grid transfer silver · Aluminum metal paste 12. Baking joints Alternative embodiments of the method are possible Careful consideration. In a preferred alternative embodiment, the figure is depicted in the wafer 12 with a diffusion barrier layer 9, such as a titanium dioxide paste, applied such that a space between a pair of mutually adjacent diffusion barrier layers 90 will be in the next-step shot. Used as a positive polarity grid. This is followed by steps 1 through 4 of the above, resulting in the apparatus of Figure 4A. However, after the disc diffusion step is used, for example, using POC13 (30 to 60 ohms/square), a device with a diffusion layer 92 is produced. Alternatively, other dopants may also be used. Then, using the above-mentioned residual steps, the scale glass formed during the diffusion of P〇C13 is invaded, and the diffusion barrier is protected from the original place. Nitride is conventionally deposited by electropolymerization assisted chemical gas accumulation (PECVD) or other methods and materials for purification. Qianhua Weiji in _ (not shown, the negative polarity is connected to the 26 1296858 point silver grid is transferred by screen printing, the positive polarity contact silver · aluminum grille is transferred by screen printing, and the wafer is baked "The result, as shown in FIG. 4c, is a battery with a diffusion barrier layer 90, a positive polarity screen transfer silver aluminum or aluminum grid substrate 96, and a negative polarity screen transfer silver grid substrate. 98. As shown in FIG. 4C, the screen printed positive grid substrate 96 may partially overlap with a portion of the diffusion barrier layer 9' or may be entirely placed on the side edge of the diffusion barrier layer 9〇. The name of the screen printing (which may be an I-lu alloy, such as silver····································································· 4C. However, at the time of baking, the metallization of the aluminum-bottom forms a P+ layer to replace the existing n+ diffusion layer. There may be a silver-aluminum or aluminum lattice in which the frit is contained in the screen of the positive electrode. In the gate substrate 96. Thus, the n+ region under the p-type contact is successfully over-blended; that is, one pass The puncture joint of the n+ region is made of a p-type substrate. In another derivative variation, the in-dopant metal is baked at a temperature exceeding the aluminum-bismuth eutectic temperature, resulting in the contact region also being Φ added to the stone. In the evening, as shown in FIG. 4D, when baking, the screen of the n+ diffusion layer 92 in the vicinity of the positive electrode is transferred to the silver. The aluminum or aluminum grid substrate is shamefully covered by the grating substrate. Excessively-mixed, resulting in a junction 96. In yet another particularly preferred embodiment, the diffusion barrier layer comprises a source of time dopants, whichever is preferred. The diffusion layer of the plate is transferred, such as a titanium dioxide paste containing a single compound, such as a boron oxide species in a certain embodiment. As a paste of boron diffusion barrier 27 1296858 layer 94 Containing a small amount of _ diffusion layer (4), such as the latter P-type body can be used or formed to form a diffusion barrier «including the blended dielectric paste, including but not limited to, gallium or steel is the highest priority Is - or more of the former oxidized compound. In an example, the diffusion layer provides over-pf+ doping with oxide as a priority. Alternatively, boron or other P-dopant barrier layer can be sprayed, ink-jetted, or screen-transferred. When the scale is diffused into the human eve, (4) the blending region, the P-type receptor in the dielectric preferably diffuses into the substrate at the same time, producing a P-type region while saving a step at the same time. Thus, after the screen printing and the boron diffusion barrier layer (10) are baked, the diffusion of the above phosphorus is used, for example, using P0C13 (30 to 60 ohms/square), resulting in co-diffusion with the disk. As shown therein, the resulting structure includes an n+ diffusion layer, preferably diffused to about 30-50 ohms/square as in some examples, and the diffusion layer 100, preferably diffused to about 100-500 ohms. / square as in the same example. Next, the phosphor glass formed during the diffusion of P0C13 is etched away by the above etching step, and the boron diffusion barrier layer 94 is left in place. The tantalum nitride is conventionally deposited by plasma assisted chemical vapor deposition (PECVD) or other methods and materials for passivation. After the tantalum nitride is deposited on both sides (not shown), the 'negative contact silver lattice thumb is transferred by screen printing, and the positive polarity contact silver · Ming grille' or more preferred is aluminum grille, The screen is transferred and the wafer is baked. As a result, as shown in FIG. 4G, a battery with a boron diffusion barrier layer 28 1296858 94, a positive polarity screen transfer silver: a Ming or aluminum grid substrate %, and a negative polarity screen transfer silver grid Substrate 98. As shown in FIG. 4G, the screen printed positive grid substrate 96 may partially overlap with a portion of the barrier layer 94, or may be entirely placed on the boron diffusion barrier layer 94 (not shown). Between the side edges. The screen printed aluminum (which may be an aluminum alloy such as silver: aluminum, or may be substantially substantially aluminum) is applied to the existing n-type diffusion layer as shown. However, at the time of baking, the metallization of the aluminum-bottom forms a mouth + layer. • Replaces the existing rvf diffusion layer. There may be a frit included in the positive: screen or silver plate 96 printed on the positive screen. Thus, the # region below the p~-type contact is successfully over-blended; that is, a puncture contact through the n+ region is made with a p-type substrate. In another variant, the dopant metal is baked at a temperature above the aluminum-bismuth co-dissolution temperature, causing the contact region to also be added to the alloy. Thus, as shown in FIG. 4G, when the paste is being baked, the silver: aluminum or aluminum grid substrate 96 in the n+ diffusion layer 92 adjacent to the positive screen is partially over-matched by the aluminum in the grid. And a contact 96 is formed adjacent to and in contact with the p+ diffusion layer 1〇〇. In yet another preferred embodiment, a diffusion barrier layer 9 is applied as shown in Figure 41, followed by an n+ diffusion step, such as a phosphorus diffusion step using POC13 (30 to 60 ohms/square) to produce an n+ diffusion layer. 92. After the tantalum nitride is deposited on both sides (not shown), the negative contact silver grid is transferred in screen, and the positive contact silver: aluminum grid, or more preferably the aluminum grid, is Screen printing. The junction 29 1296858 - S ' is not shown in Figure 4J is a battery with a diffusion barrier layer 9G, a positive-working screen transfer silver: 绍 or a secret grid substrate 96, which contains a refining block or other material to drive the substrate 96 passes through the barrier layer 90, and the negative grid plate transfer of the silver grid substrate 98. The screen transfer imprint (which may be an alloy of inscription, such as silver: or may be substantially in general! g) is applied directly to the diffusion barrier layer 9', as shown in Figure 4J. However, at the time of the bake, the metallization of the bottom-bottom drives the thinning through the barrier, as shown in the class 'and!', the formation of the seed layer below it φ (not shown). In a related preferred embodiment, as shown in Figure 4L, a diffusion barrier layer 9 is applied followed by an n+ diffusion step, such as a phosphorus diffusion step using POC13 (30 to 60 ohms/square), resulting in #diffusion Layer 92 is followed by application of a patterned anti-56. After the application of anti-56 and the deposition of nitride on both sides (not shown), the engraving step is used to invade and de-expose the exposed portion of the diffusion barrier layer 90, as shown by the off. On the side of the encapsulation layer (10), the surface of the anti-money agent is removed and the wafer is cleaned. A negative polarity contact silver grid 98 is transferred by a stencil, and a positive polarity contact silver · · chirp 96, or more preferably an Ilu grid 96, is transferred by screen printing. As a result, as shown in the figure, the 疋-battery is provided with a diffusion barrier layer 9 〇, a positive polarity screen transfer silver: an aluminum or Ming grid substrate 96, and a negative polarity screen transfer silver grid substrate. 98. Screen transfer _ (which may be -_alloy, such as silver · · ·, or may be substantially intrinsic), applied to the diffusion barrier 30 1296858 mask 90 removed by the anti-melting agent and rhyme steps There is a pattern part, as shown in Figure 4M. When this is properly baked, the metallization of the bottom _ causes direct contact with the 2, as shown by the reward, and together with the inscription forms a p+ layer below it (not shown). In yet another side and alternative, the process sequence can be used to create a patterned diffusion layer using a different transfer diffuser source as a diffusion barrier. As discussed herein, different paste materials are commercially available, such as by Ferro Corporati, for use in the process of _ or _ diffusion, and can be used to transfer the _ layer. Embodiments Deducted The other embodiments are possible and can be carefully considered when using a p__ wafer with a diffusion-doped layer. It is also possible to include, for example, an n+ diffusion paste which is preferably a component which does not comprise a diffusion barrier layer for forming a region of higher n++, preferably a grid comprising holes 30. The screen transfer method can be applied by applying these pastes. After application, the pastes are dried to remove the core material f and the volatile material = and are baked at a high temperature to diffuse the dopant into the human form. The paste passes "oxides with dopants; these oxides can be removed by hydrofluoric acid after the dopants have diffused. This process may be arbitrarily modified to produce a selectivity in solar cells. In this embodiment, the holes and the back surface are preferably densely matched to obtain a low resistance, but the front surface is blended lightly, and the car and the car are smashed. In the above needle production, step 6 will be replaced by a smaller amount of P0C13 diffusion layer (preferably 80 to loo ohms/square) of 31 1296858. After step 9, the second time, dense POC13 diffusion (preferably Less than about 2 ohms/square) will be performed, preferably followed by fluoric acid removal of the phosphorus diffusion glass and certain nitrides to form an anti-reflective coating on the front surface. This modified variant works best when only a small amount is deposited in the hole, and preferably does not exist there at all; such an anisotropic PECVD process would be a priority.

Spin-on glass diffusion barrier In the other-implementation, the back-contact battery is in the process of spin-coating (SOG) deposition and screen transfer resistance (4). Spin-on-glass (SOG) is used as a barrier layer in the emitter diffusion step ("diffusion barrier oxide" SOG system is deposited in the usual way, such as by spin coating or spray coating. It is dried and densified in the furnace. It is best that the Na is also used for any of a variety of different dielectric materials. So s〇g may be Shi Xi Tu

(Sl〇2): acid-destroyed glass (10)), deoxidized oxides of other P-type dopants (Sui, Shao, indium, etc.), Weiweili (10), titanium dioxide (10) 2), and scales thereof. This - the SQG is known to the people in Qianxian, and (10) her 1 secret secretary (_, Pennsylvania) supplies all kinds of observation materials. The dioxometer is advantageous because of the interface re-combination formed between the dioxide wafers. Royal ____ has an additional source of dopants that act as decay or phosphorus. A lightly blended junction below the densified 32 1296858 BSG or PSG layer helps improve battery performance and passivate the surface. SGG (4) has the additional advantage of being non-toxic and easy to manufacture. Just after (10) technology, such as the disclosure of the country's patent number 5, coffee, which uses, for example, phosphine and Wei or diguan and Wei compounds, the compounds are toxic and specialization depends on management domain equipment . The SOG adds a pattern to the first transfer and the engraved side, and a chemical side is performed. The transfer can be turned over, but other transfer methods such as ink jet printing, stencil printing, lithography, etc. can also be used. Any of a variety of different materials can be used as a side anti-money agent. As an anti-side requirement, it is only transferable and has an anti-surname effect on chemical invasive liquids. Aqueous solutions of hydrofluoric acid are widely known as oxide material etchers. A representative process sequence is described below to make a back contact type EWT solar cell using s〇G as a diffusion barrier. A similar process sequence can be used for other back contact cell structures such as MWA, MWT, or backside-junction solar cells. The screen-transferred silver grid of the negative polarity and the positive polarity contacts is preferably baked by tantalum nitride so as to be in contact with the crucible, which is well known in the related art. A p-type germanium semiconductor substrate is provided in a process sequence for forming a back contact type EWT solar cell using a pattern transferred by a screen transfer resist. Usually, the enamel substrate is typically polycrystalline or polycrystalline, but other types of slab substrates may also be used, including but not limited to single crystal 33 I296858 ο first and second steps, laser drill Holes and etching are as described above. In the third step, SOG is applied. As discussed above, the SOG acts as a barrier during the emitter diffusion step and is optional but also preferred as a deposition dielectric material. The SOG is deposited by conventional common methods, such as spin coating or spray coating, or by other means such as immersion in a solution containing SOG material, and then placed in a high temperature furnace for drying and densification. Preferred as s〇G is alumina (Si02), borosilicate glass (BSG), BSG mixed with additional p-type dopants, phthalic acid filled glass (PSG), or titanium dioxide (Ti〇2) ). Typically, SOG is typically applied to the back surface and is produced to a thickness of about 〇 1 to 1 μm after densification in a high temperature furnace. After the bribe of SOG, #有-层抗-transfer, the simplified transfer method is used, but the alternative method of 丨人带 pattern is also available. The anti-paving pattern provides at least a group of fine grids, which are typically in the pattern of mutually matching contact grids in this area of the towel, such as the one provided here. Any (4) merger _ leak may be used; however, 'reporting important should not be ambiguous _ material, but using a chemical resistance rhythmic material, and specifically clear is an acid-resistant substance, So that s〇G is not removed from the patterned area when the wafer is subjected to acid residue processing. Read the replenishment step of the money agent, and re-send the wafer to remove the SOG outside the coverage area of the 34 1296858 agent. Any suitable acid residueing process may be used as long as the resist is not removed by the chemical etchant solution. In a preferred embodiment, an aqueous solution of hydrofluoric acid, such as 1% hydrofluoric acid, is used. Any conventional method of applying an etchant may be used, including immersing the wafer in a tissue containing fluorofluoric acid. SGG is removed from the hole during this step, and from the flat front and back surfaces that are not covered by the resist. After the etching step, the resist is removed and the wafer is cleaned. The method of using the bath or other means for removing the resist depends on the resist used. The wafer can also be further cleaned using a suitable chemical cleaning solution, such as those containing hydrogen peroxide and sulfuric acid. The resulting product is a patterned wafer in which S0G appears only in the area where the resist is applied. _ A relatively dense phosphorus diffusion layer is applied in a common and common manner, including the use of gas phase diffusion of liquid sad P0C13 to produce a surface resistance of 4 〇 to ohms/square. However, other sources or methods of diffusion may also be used, including the application of liquid source methods such as coating, soaking or spin coating, or solid sources such as solid sources. A material, such as a pentoxide stone 4, is heated to a temperature of enthalpy. In general, p〇Q3 in the normal gas state is preferred. After the phosphorus diffusion step, the wafer is again subjected to chemical etching, for example using hydrofluoric acid. Sufficient hydrofluoric acid is applied for a period of time to render the front and back surfaces water-labile, which can be determined by the ''covering π effect produced by the hydrofluoric acid aqueous solution 35 1296858 when the wafer is removed from the solution. After the second etching step, the bare front surface of the front side and the back side is preferably, but is also optionally, passivated by deposition of a dielectric layer. Nitride may be conventionally deposited by PECVD, or other methods and materials for passivation may be used. As discussed herein, if the back surface diffusion-barrier oxide is not removed by, for example, chemical etching, this is feasible under certain conditions. As discussed above, the passivation step of the back surface can be omitted.

After the passivation, the negative-polar grid contacts and the positive-polar grid contacts are then applied. Any common common grid metal method may be used, for example, a negative-polar grid contact to transfer a silver paste to a screen, and a positive-polar grid to a transfer-view. (d) may be made by a combination of silver or silver in a retreaded form, as appropriate, a formula of a residual state, which I may additionally comprise a binder, a solvent, and a substance known in the art. In order to make a paste which can be used for screen printing. It is also possible to use it in a paste formulation which contains components which can be nitrided (see Μ. 's_) ', for example, a glass block. The wafer is then baked to metallize the grid contacts. = It can be seen that the method may be as follows: it is also implemented by the sub-counties of the same steps ", 3 π 者*, and the output of the desired product: 1·Laser drilling 36 1296858 2. Alkaline I insect engraved wafer 3. Application of spin-on glass (s〇G) 4. Spin-coated glass (S0G) densification 5. Transfer resistance | insecticide 6 · etching spin-on glass (S0G) 7 · off In addition to the resist and clean the wafer 8 · Gasification barrier (P0C13) diffusion (40 to 6 〇 ohm / square) φ 9 · Hydrogen fluoride | insect engraving, both surfaces are threatened with water ιο · front surface application Plasma-assisted chemical vapor deposition (PECVD) nitride 11·post surface application of plasma-assisted chemical vapor deposition (QDECVD) nitride 12·negative negative grid transfer silver metal paste 13·for positive polarity grid transfer Ink silver aluminum paste 14. Baking joints As shown in Fig. 5A, the holes 52 are drilled into holes by a laser and the alkaline etching is completed on the substrate #, preferably the ?-type wafer 50. A P-type spin-on glass 54 is then applied to the back surface as shown in Figure 5B, such as chopped limestone glass (Β%), or an oxide of bsg or other SOG mixed with other p-type dopants. For example, gallium, indium or aluminum. A transferred etch resist 56 is then applied to the pattern corresponding to the desired grid. After the etching step, such as hydrofluoric acid etching, a p-type patterned spin-on glass 54 is formed as shown in FIG. 5C. The P-type patterned spin-on glass in the hole 52 is also removed during the etching step, so that the structure under the remaining 37 1296858 is composed only of the patterned p-type s〇G covered by the resist 56. . As shown in Fig. 5D, the resist is then removed, so that only the patterned P-type SOG 54 remains on the wafer 50. Next, a dense amount of phosphine chloride diffusion 〇4 〇 to 60 ohms/square is performed, and a crystallization diffusion layer 64 which produces an n-type diffusion layer is shown in Fig. 5E. Figure 5F shows the wafer after the hydrofluoric acid residue step and removal of the dopant SOG glass 54. Figure 5 (showing the completed solar cell, the negative-polar grid contact 72 after the silver paste is applied to the negative polarity grid and the silver: aluminum paste I material is applied to the positive polarity grid. And silver: the result of a positive-polar grid junction 70 of aluminum. A layer of tantalum nitride deposited as pecvd, which can be optionally applied, is not shown here. In an alternative embodiment, the SOG material Apply to the desired pattern, . Gradually ink, lithographic transfer, or use the appropriate fresh method to produce the Na material of the belt. By using this method, it is possible to eliminate the resistance. Corrosion printing and related remnants and removal steps result in considerable reduction in the complexity of the process steps. Spin-coated glass as a source of expansion of the blue house gold replacement in another embodiment, this The invention provides an alternative method for producing a back contact type EWT battery using a transferred SOG material or s〇G applied by spin coating or spray coating techniques. The process is also applied with a s〇G and Add a pattern to start, ambiguously the range of P-type contact areas. Or This process can start with the transfer and baking of the glaze paste. A SOG containing n_ tamper (usually 38 1296858 is tantalum silicate glass) is applied to the back surface and overlaid on the previous pattern. The separate high temperature furnace processing step simultaneously diffuses phosphorus and boron into the desired pattern on the back surface. As shown in Figure 6A, the holes 52 are drilled with a laser and are alkaline etched on the enamel substrate. Is a P-type germanium wafer 50. A p-type spin-on glass (S0G) 54 is then applied to the back side as shown in Figure 6B, such as a sulphuric acid glass (bsg) or BSG and other P-type doping An oxide of the substance, such as gallium, indium or aluminum, followed by a transfer of the I-etch resist 56 applied to the pattern of the desired grid. In the etching step, for example, hydrofluoric acid, the result is A p-type patterned s〇G 54 is formed as shown in Figure 6C. The p-type SOG in the hole 52 is also removed during the etching step, resulting in the remaining structure being only patterned by the p-type 54 The portion covered by the anti-surplus agent 56 is composed. As shown in Fig. 6D, the resist is then removed, so that only The patterned P-type 3〇〇 remains on the wafer 5〇. Next, an η-type SOG 6G is applied to the back side to cover the chopped fill hole 52 and covers the SOG 54. Any n-type SOG may be It is preferably sulphuric acid scale glass (PSG). After the application of η-type S0G 60, the wafer is baked at a high temperature, for example, in an oxidizing environment, _(TC rides for 60 minutes. As shown in the figure _, the η-type diffusion layer 62 and the dense p-type diffusion layer 64 are generated. The light η-type diffusion layer 66 has a large touch to 丨_m/square. The typical value of the resistance value is also introduced to the top surface. The light n-39 type diffusion layer 66 may be introduced by automatic doping, as shown in FIG. The front surface of the 82 is exposed to the rear surface of the wafers 82, 84 coated with the n-type s 〇 G 60, so that the light diffusion layer 66 is formed by the upper type 8 (6 冗 6 〇 Or the diffusion of other η-type dopants. In Fig. 7, the arrow represents the direction of diffusion, and a diffusion layer 66 is produced. Thus, in this embodiment, the light diffusion layer 66 contains phosphorus or other dopants having a lower concentration than the inner walls of the holes 52. Alternatively, a s?G having a relatively low phosphorus content may be applied to the front surface (not shown) and simultaneously diffused into the front surface. The differences in these processes are described below. These differences in any embodiment result in a more optimized diffusion profile with higher conversion efficiency. Figure 6G shows the wafer after the fluorinated acid|insect step and after the dopant glass is removed. Figure 6H shows the finished solar cell, which is a silver paste applied to the negative polarity grid and a negative-polar grid junction 72 and silver after the silver: aluminum paste is applied to the positive polarity grid. The result of the positive-polar grid contact 7〇. The tantalum nitride layer deposited by PECVD, which can be optionally applied, is not shown here. The following sequence list illustrates an embodiment of the manufacturing sequence of lunar contact EWT solar cells using η-type and p-type s〇G and automatic blending methods. It is also understood that some of these steps may not be The order of _ is executed, and still produces the product that you want. 1. Laser drilling on 矽 wafer 1296858 2. Alkaline etching 3. Apply spin-on glass (s〇G) with p-type dopant to the back surface 4. Place spin-on glass (SOG) Densification 5. Transfer resist 6. Hydrofluoric acid residue 7. Remove the resist and clean the wafer. 8. Apply spin-on glass (9) G) with η-type dopant to the back surface. 9. Indentation of the official south temperature furnace dopant (the wafer can be randomly arranged to allow the automatic blending of the front surface to be carried out). 10. Hydrogen fluoride surname 11. Application of plasma assisted chemical vapor deposition (PECVD) Nitride on the front surface 12. Application of plasma assisted chemical vapor deposition (pECVD) nitride on the back surface 13. Negative polarity thumb transfer silver paste 14 · Positive polarity grid transfer silver · Aluminium Paste 15. Baking Joints The following sequential list illustrates an alternative embodiment of the tantalum-type and P-type SOG and additional S0G silk-face blending as a back-contact EfT solar cell fabrication sequence. It is also being understood that some of the steps may be performed in a different order than listed, and that the desired product is still available. 1. Laser drilling in Shixi wafer 2. Quantitative | Insect 1296858 3. Apply spin-on glass (SOG) with p-type dopant to the back surface 4. Place the spin-on glass ( S0G) Densification 5. Transfer resist 6. Hydrofluoric acid residue 7. Remove the resist and clean the wafer 8. Place the spin-on glass with η-type dopant (s〇G Applying to the back surface 9. Densification

10. Apply spin-on glass (S0G) with low concentration η-type dopant to the front surface. 11·Injection of dopants in tubular two-temperature furnace. 12. Hydrogen fluoride|Insect 13. Application of plasma assist Chemical vapor deposition (PECVD) nitride on the front surface 14 · Application of electropolymerization assisted chemical vapor deposition (PECVD) nitride on the back surface 15 · Negative polarity grid transfer silver paste

16·Transfer silver for positive polarity grid: Shao paste 17. Baking joints can be chosen, the front surface diffusion can be carried out in another step, which can use the τ type high temperature furnace instead of the tube type high temperature furnace . The previous method can be re-used or specifically addressed by the counter. A similar achievement is achieved by substituting the general requirements and/or operating conditions of the present invention in place of the previous method. 42 1296858 Although the present invention has been described in detail with respect to these preferred embodiments, other Bega examples It is possible to achieve the same result. Variations and modifications of the present invention appear to be unremarkable to those skilled in the art, and all such modifications are intended to be equal. The file is included in the scope of the additional patent application. All reference documents, application cases, patents and distributions mentioned above are included here as reference materials. ^ [Simple diagram description]

The accompanying drawings are included in the specification as a part of the towel; - the drawings "detailed" or more embodiments, together with their written description, are used to explain the invention. The purpose of one or more prioritized implementations (IV) of the present invention is not to turn to the invention. In this statement: w

1 series-like schematic diagram of the back contact type solar power. The _--crystal_' has been drilled and sided through the back contact cell process sequence of the present invention, and Figure 2B is a top view of a portion of the wafer of Figure 2A. 3A is a cross-sectional view of the wafer of FIG. 2 in the process of the back contact cell process of the present invention, wherein the phosphor _ and the scatter source paste are transferred; __ the surface contact cell process of the present invention. The cross-section of the dopant in the high-temperature diffusion; the fine-touch _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ A view of the top of the job. 43A to 4N are cross-sectional views showing the steps of manufacturing a back contact type EWT battery using the transferred diffusion barrier layer of the present invention. 5A to 5G are cross-sectional views showing the steps of manufacturing the back contact type EWT battery by the application of the spin-on glass (9) 本) of the present invention. Figures 6A through 6H are cross-sectional views showing the steps of fabricating a back contact type EWT cell using the application of multiple spin-on glass (s〇g) of the present invention. Figure 7 is a cross-sectional view showing the automatic blending procedure of the present invention during the tube-type diffusion during the wafer-holding vertical state. [Description of main component symbols] 12····Flat wafer 34··· .Material 34···•Bon-diffusion source paste 30···. Hole 36··· • Phosphorus-diffusion layer 38· ·· • Lin-diffusion layer 40··· • Boron-diffusion layer 42··· • Negative-polar grid contact 44··· • Positive-polar grid contact 50··· • Ρ-type twin Circle 52··· . Hole 54··· • Ρ-type spin-on glass 56··· • Resist 60··· .n-type SOG 62··· .η-type diffusion layer 64··· • Ρ - Type diffusion layer 66 · · · η - type diffusion layer 70 · · · Positive grid contact 72 · · · Negative grid contact 80, 82, 84 · · · · Wafer 90··· . Diffusion barrier layer 92··· .n+ diffusion layer 94··· • boron diffusion barrier layer 96··· . Peach substrate 98··· • Silver grid substrate 100····Ρ+ diffusion layer 44

Claims (1)

1296858 X. Patent Application Range: 1. A method of fabricating an EWT solar cell, the method comprising the steps of: providing a semiconductor wafer having a front surface and a back surface and extending from the surface to a hole in the back surface; applying a first dopant diffusion source to the pattern pattern containing the back surface holes on the back surface; applying a second dopant diffusion source on the back surface to not including the The pattern pattern of the surface holes is merged into the semiconductor wafer from the first doping diffusion_the second dopant diffusion source. 2. The method of claim 1, wherein the semiconductor wafer package comprises a first dopant source comprising phosphorus and a second dopant source comprising boron. The method of claim 2, further comprising applying a first dopant diffusion source comprising phosphorus to the pattern of the front surface comprising the front surface aperture. The method of claim 1, wherein at least a portion of the hole in the step of applying the first dopant diffusion source is filled with the first type of dopant source. 5. The method of claim 1, further comprising the steps of: affixing the cast wafer with an acidic solution after the diffusion step; applying two dielectric f layers that are passivating At least to the surface of the surface of the semiconductor wafer that has been engraved, the at least part of the pattern of applying the first-conducting metal grid to the rear surface including the pattern of the first dopant diffusion source pattern is removed, and The second conductivity type 45 l296858, a Li^ type metal grid is applied in at least a part of the pattern pattern of the second surface of the second impurity diffusion pattern. An EWT solar cell characterized in that the solar cell of the book is produced by the method described in claim 1 of the patent application. / 7 - A method for producing a full-wrap (10) τ) solar cell, the method package, the following steps provide a semiconductor wafer having a front surface and a rear surface and a hole extending from the surface L to the rear surface , force σ—the diffusion barrier layer to the back surface does not contain the post-turn surface hole in the job pattern; clean the wafer; diffuse the first dopant into the human wafer; The first-conducting type of gold is only available. Grid 17 to the back surface containing the pattern of the back surface holes, and a pattern of applying a second 'private type metal grid to the back surface separated by the diffusion barrier pattern and the first conductivity type metal grid In the style. 8. The method of claim 7, wherein the semiconductor wafer comprises a germanium-conducting type germanium, the first dopant comprises phosphorus, the first conductivity type metal grid comprises silver, and the second The electrically conductive metal grid comprises aluminum. 9. The method of claim 8, further comprising the step of applying a passivating dielectric layer to at least a portion of the surface of the port-conducting pattern after the etching step; Wherein the resistance caused by applying the first dopant phosphorus source is between about 30 and 60 ohms/square (Ω/sq); and wherein the step of applying the first and second conductivity type metal grids comprises transferring the grating pattern Style and supply, j: 咅 0 46 1296858 / '. ΙΊΣΤΤ................................................................................................................................................................................................................................................................................ A second dopant of opposite conductivity type. 11. A method as claimed in the patent application Sj_, wherein the first dopant comprising 4 Ail forming part of the expansion mask comprises a Si Peng. 12. The method of claim 5, wherein the first dopant and the second dopant are simultaneously diffused into the wafer. 13· - Shed solar cell, characterized in that the solar cell is produced by the method described in item 7 of the special machine. A method of fabricating a full body encapsulation (EWT) solar cell of 14β, the method comprising the steps of: providing a semiconductor wafer having a front surface and a rear surface and a hole extending from the surface to the rear surface; Spin-coated glass (Na) expanded-diffused to the back surface; applied a pattern of resistance to the hole that does not include the back surface hole, 'I am inscribed on the circle to remove the first spin-on glass (9)G) The part covered by the patterned Luk _; removes the anti-surname agent from the wafer; diffuses the first dopant into the ' round' wafer! _ becoming at least the remaining first spin-on glass (S〇G); and applying the first electrical metal grid to the pattern of the back surface containing the back surface holes, and the second conductive type of metal The grid is applied to the pattern of the back surface containing the pattern of the resist pattern. The method of claim 14, wherein the semiconductor wafer 匕3 石石帛 dopant comprises filling, and applying the first spin-on glass (10) is by spin coating or tilting Methods such as the method and the high temperature furnace are difficult to process. 47 Ί 858 858 Ί Ί Ί Ί Ί Ί Ί Ί Ί ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... Dopant. Guanlan Sun Qianchi's ship is based on the method described in item U of the patent application scope. a method for producing a full-wrap (10) solar cell of a projectile, the method of providing a semiconductor wafer having a front surface and a rear surface and a hole extending into the rear surface of the surface; The first spin-on glass (9) G) of the first dopant is applied to the back surface; an anti-money agent is applied to the pattern pattern not including the back surface hole; (10) is applied to the wafer to remove the first spin-on glass ((10) is not a portion of the patterned anti-side cover; removing the anti-_ from the wafer; applying a second spin-on glass (SOG) comprising a second dopant of the I-conducting type opposite the first dopant To the rear surface; the wafer is baked to diffuse the first dopant and the second dopant into the wafer'. The crystal is engraved to at least remove the remaining first and first spin coatings Glass (SOG); and applying a metal grid of the first conductivity type to the rear surface including the age face, the metal grid of the second conductivity type is applied to the pattern of the back surface containing the pattern of the resist pattern 19. The method of claim 18, which additionally includes the application of a step of three spin-on glass (SGG) to the front surface of the wafer, the third spin-on glass (SOG) comprising a second dopant at a lower concentration than in the second spin-on glass (S0G) 20. The method of claim 18, wherein the baking comprises: 48 • 1296858 96Πζ i""""""" The front surface is advanced to the rear surface so that the second dopant from the second spin-on glass (S0G) on the back surface of the first wafer is diffused to the adjacent front surface of the immediately adjacent second wafer. An EWT solar cell characterized in that the 太阳能^τ solar cell is produced by the method described in claim 18 of the patent application. 49 1296858 • V. Summary of Chinese Invention: A method of manufacturing a full-emulsion (EWT) back contact solar cell and a battery fabricated in this manner. Some methods provide a higher concentration of dopant at the conduction path compared to the average concentration of dopants on the front or back surface, which increases the efficiency provided. There are a number of ways to provide selective doping of the pores to form a feed channel using the transfer. Other methods are used to spin-coated glass substrates containing dopants. • VI. Abstracts of English Inventions: VII. Designation of Representative Representatives: (1) The representative representative of the case is: (3Α). (2) A brief description of the symbol of the representative figure: 12· · · · Plane wafer 34 - paste 34 · · · · Boron - diffusion source paste _ VIII, if there is a chemical formula in this case, please reveal The chemical formula that best shows the characteristics of the invention. IX. Description of the invention: [Technical field to which the invention pertains] The related application is a "contact fabrication of Emitter Wrap" -Through Back Contact Silicon Solar Cells)" by name, Peter Hacke and James Μ Gee, seen in the US Public Service 3