CN110656323A

CN110656323A - CVD equipment for manufacturing HIT solar cell, complete set of CVD equipment and film coating method

Info

Publication number: CN110656323A
Application number: CN201910921743.5A
Authority: CN
Inventors: 汪训忠; 其他发明人请求不公开姓名
Original assignee: SHANGHAI LIXIANG WANLIHUI FILM EQUIPMENT Co Ltd
Current assignee: SHANGHAI LIXIANG WANLIHUI FILM EQUIPMENT Co Ltd; Ideal Energy Shanghai Sunflower Thin Film Equipment Ltd
Priority date: 2019-09-27
Filing date: 2019-09-27
Publication date: 2020-01-07

Abstract

The invention provides a CVD device, a CVD device set and a film coating method for manufacturing an HIT solar cell. The CVD apparatus includes: a loading chamber configured to receive a tray carrying silicon wafers from a loading position; a plurality of CVD process chambers configured to receive a tray carrying a silicon wafer and to sequentially deposit an I/N type or I/P type amorphous silicon thin film on one side of the silicon wafer by respective intrinsic and impurity-doped CVD processes; an unloading chamber configured to receive a tray carrying silicon wafers having completed the native and doping CVD processes and convey them to a discharge position to discharge the silicon wafers from the tray; and the transfer cavity is connected with the loading cavity, the plurality of CVD process cavities and the unloading cavity and is configured to receive the tray carrying the silicon wafers from the loading cavity or any CVD process cavity and correspondingly transfer the tray to any available CVD process cavity or any unloading cavity. The invention can deposit I/N type or I/P type amorphous silicon film in the same cavity, and can effectively improve the integration level of equipment, reduce the automation difficulty, reduce the occupied area and improve the productivity of the equipment.

Description

CVD equipment for manufacturing HIT solar cell, complete set of CVD equipment and film coating method

Technical Field

The invention relates to the field of solar cell manufacturing, in particular to CVD equipment, complete CVD equipment and a film coating method for manufacturing a heterojunction solar cell.

Background

The thin film/crystalline silicon heterojunction solar cell (hereinafter referred to as heterojunction solar cell, also called HIT or HJT or SHJ solar cell) belongs to the third-generation high-efficiency solar cell technology, combines the advantages of the first-generation crystalline silicon and the second-generation silicon thin film, has the characteristics of high conversion efficiency, low temperature coefficient and the like, particularly has the conversion efficiency of the double-sided heterojunction solar cell reaching more than 26 percent, and has wide market prospect.

The core process for producing the HIT solar cell is a double-sided I-type amorphous silicon thin film passivation and N, P doping technology, which is currently mainly implemented by a PECVD (Plasma Enhanced Chemical Vapor Deposition, abbreviated as PECVD) coating apparatus, and also implemented by a Hot Wire Chemical Vapor Deposition (Hot Wire CVD, abbreviated as HWCVD) (also called catalyst Chemical Vapor Deposition, abbreviated as CAT-CVD) coating apparatus.

The existing equipment capable of being used for large-scale mass production of HIT solar cells is provided with a film forming process cavity for 4 layers of amorphous silicon films of double-sided I and N, P respectively, and the film forming process cavities are arranged along a straight line or a U shape corresponding to four CVD process cavities, so that the equipment is low in integration level, complex in automation, high in cost, large in occupied area, low in relative productivity and low in cost performance. In addition, the conventional PECVD equipment needs to heat the corresponding silicon wafer to the range of 100-.

Therefore, how to provide a CVD apparatus and a coating technique capable of improving the integration level and the productivity of the apparatus has become an urgent technical problem to be solved in the industry.

Disclosure of Invention

In view of the above problems of the prior art, the present invention proposes a solution 1 of a CVD apparatus for manufacturing a heterojunction solar cell. In claim 1, the CVD apparatus comprises: a loading chamber configured to receive a tray carrying silicon wafers from a loading position; a plurality of CVD process chambers configured to receive the tray loaded with the silicon wafer and to sequentially deposit an I/N type or I/P type amorphous silicon thin film on one side of the silicon wafer through an intrinsic CVD process and a doping CVD process, respectively; an unloading chamber configured to receive the tray carrying the silicon wafers having completed the intrinsic CVD process and the impurity-doped CVD process and transfer them to a discharge position to discharge the silicon wafers from the tray; and the conveying cavity is connected with the loading cavity, the plurality of CVD process cavities and the unloading cavity and is configured to receive the tray which is loaded with the silicon wafer and comes from any one of the loading cavity or the plurality of CVD process cavities and correspondingly convey the tray to any available CVD process cavity or the unloading cavity.

The invention also provides the CVD apparatus according to claim 2 of claim 1, wherein the CVD apparatus comprises a PECVD apparatus and a HWCVD apparatus.

The invention also provides a CVD apparatus according to claim 3, wherein a preheating module is further provided in the loading chamber, and the preheating module is configured to preheat the silicon wafer to a temperature in the range of 25-250 ℃ before the silicon wafer enters any available process chamber of the plurality of CVD process chambers.

The invention also provides the CVD apparatus according to claim 1, wherein the plurality of CVD process chambers further have a cleaning function of cleaning the chamber itself and an empty tray introduced therein.

The present invention also provides the CVD apparatus according to claim 5 of claim 1, wherein the plurality of CVD process chambers are each configured to: heating the silicon wafer to a preset film forming temperature, providing gas required by the intrinsic CVD process, decomposing the gas by utilizing PECVD plasma or thermally dissociating the gas by utilizing HWCVD so as to deposit an I-type amorphous silicon film on one surface of the silicon wafer; and providing gas required for the doping CVD process, decomposing the gas by using PECVD plasma or thermally dissociating the gas by using HWCVD, thereby depositing the N-type or P-type amorphous silicon film on the I-type amorphous silicon film and forming the I/N-type or I/P-type amorphous silicon film.

The invention also provides a 6 th technical scheme of the CVD apparatus according to the 5 th technical scheme, wherein the preset film forming temperature of the silicon wafer is within the range of 100-300 ℃, the gas required for carrying out the intrinsic CVD process comprises silane or silane and hydrogen, and the gas required for carrying out the doped CVD process comprises silane or silane and hydrogen, and also comprises phosphane or diborane or trimethylboron.

The present invention also provides the CVD apparatus according to claim 7 of claim 1, wherein the CVD apparatus comprises a single-layer apparatus unit and a multi-layer apparatus unit, the single-layer apparatus unit comprising the loading chamber, the transfer chamber, the plurality of CVD process chambers, and the unloading chamber in the same horizontal layer; the multilayer equipment unit comprises a plurality of single-layer equipment units which are correspondingly stacked along the vertical direction, the multilayer equipment unit comprises a multilayer loading cavity, a multilayer transmission cavity, a plurality of multilayer CVD process cavities and a plurality of multilayer unloading cavities, and the multilayer loading cavity, the multilayer transmission cavity, the plurality of multilayer CVD process cavities and the plurality of multilayer unloading cavities are respectively and integrally constructed into a loading cavity vertical column, a transmission cavity vertical column, a plurality of CVD process cavity vertical columns and an unloading cavity vertical column.

The invention also provides the CVD apparatus according to claim 8, wherein the CVD apparatus further comprises a tray pass-back device configured to transfer an empty tray from the loading position to the unloading position, wherein the silicon wafers are placed into the trays at the loading position, and the silicon wafers are taken out of the trays at the unloading position to obtain the empty tray.

The invention also provides a 9 th technical scheme of the set of CVD equipment for manufacturing the heterojunction solar cell, wherein the set of CVD equipment is used for respectively depositing a first amorphous silicon thin film selected from the I/N type amorphous silicon thin film and the I/P type amorphous silicon thin film and a second amorphous silicon thin film different from the first amorphous silicon thin film on the first surface and the second surface of the silicon wafer; the CVD apparatus set comprises: a first CVD apparatus according to any of the above technical solutions, wherein the first CVD apparatus comprises a first loading chamber, a first transporting chamber, a plurality of first CVD process chambers and a first unloading chamber, each of the first CVD process chambers is configured to receive a tray carrying a silicon wafer and sequentially deposit the first amorphous silicon thin film selected from the group consisting of I/N type and I/P type amorphous silicon thin films on the first surface of the silicon wafer through a first intrinsic CVD process and an N-type or P-type doping CVD process; a silicon wafer turning device configured to receive the silicon wafer, a first side of which has finished deposition and is blanked, from a first unloading chamber of the first CVD apparatus, and turn the silicon wafer so that the first side of the silicon wafer is exchanged with a second side opposite to the first side; and a second CVD apparatus according to any of the above embodiments, the second CVD apparatus being configured to receive the tray carrying the silicon wafer flipped over by the wafer flipping device, the second CVD apparatus including a second loading chamber, a second transport chamber, a plurality of second CVD process chambers and a second unloading chamber, each of the second CVD process chambers being configured to receive the tray carrying the flipped-over silicon wafer and sequentially deposit a second amorphous silicon thin film selected from the group consisting of I/N type and I/P type amorphous silicon thin films on the second side of the silicon wafer by a second intrinsic CVD process and a P-type or N-type doped CVD process.

The invention also provides a 10 th technical solution of the complete set of CVD equipment according to the 9 th technical solution, wherein the CVD equipment comprises PECVD equipment and HWCVD equipment.

The invention also provides the 11 th technical solution of the set of CVD equipment according to the 9 th technical solution, wherein the first loading chamber and the second loading chamber are each provided with a preheating module configured to preheat the silicon wafer to a temperature in the range of 25-250 ℃ before the silicon wafer enters any available first CVD process chamber or second CVD process chamber.

The invention also provides a 12 th technical scheme of the complete set of CVD equipment according to the 9 th technical scheme, wherein the first CVD process chamber and the second CVD process chamber also have a cleaning function of cleaning the chamber body and an empty tray entering the chamber body.

The invention also provides the 13 th technical solution of the set of CVD equipment according to the 9 th technical solution, wherein the first CVD process chamber or the second CVD process chamber for depositing the I/N type amorphous silicon thin film is configured to: heating the silicon wafer to a preset film forming temperature, providing gas required by the first or second intrinsic CVD process, decomposing the gas by utilizing PECVD plasma or thermally dissociating the gas by utilizing HWCVD so as to deposit an I-type amorphous silicon film on the first surface of the silicon wafer; providing gas required for carrying out an N-type doping CVD process, decomposing the gas by utilizing PECVD plasma or thermally dissociating the gas by utilizing HWCVD so as to deposit an N-type amorphous silicon film on the first surface and form the I/N-type amorphous silicon film; wherein the preset film forming temperature of the silicon wafer is within the range of 100-300 ℃, the gas required for performing the first or second intrinsic CVD process comprises silane or silane and hydrogen, and the gas required for performing the N-type doped CVD process comprises silane or silane and hydrogen and also comprises phosphane.

The invention also provides the 14 th technical solution of the set of CVD equipment according to the 9 th technical solution, wherein the first CVD process chamber or the second CVD process chamber for depositing the I/P type amorphous silicon thin film is configured to: heating the silicon wafer to the preset film forming temperature, providing gas required by the first or second intrinsic CVD process, decomposing the gas by using PECVD plasma or thermally dissociating the gas by using HWCVD so as to deposit an I-type amorphous silicon film on the second surface; providing gas required for carrying out a P-type doping CVD process, decomposing the gas by utilizing PECVD plasma or thermally dissociating the gas by utilizing HWCVD so as to deposit a P-type amorphous silicon film on the second surface and form the I/P-type amorphous silicon film; wherein the preset film forming temperature of the silicon wafer is within the range of 100-300 ℃, the gas required for performing the first or second intrinsic CVD process comprises silane or silane and hydrogen, and the gas required for performing the P-type doped CVD process comprises silane or silane and hydrogen, and further comprises diborane or trimethyl boron.

The invention also provides the 15 th technical means of the set of CVD equipment according to the 9 th technical means, wherein the first CVD process chamber or the second CVD process chamber in which the I/P type amorphous silicon thin film is deposited is further configured to perform a boron removal device capable of removing boron contamination.

The invention also provides a 16 th technical scheme of a coating method for a set of CVD equipment for manufacturing the heterojunction solar cell, wherein the set of CVD equipment comprises first CVD equipment, a silicon wafer turnover device and second CVD equipment, and the method comprises the following steps: (a) receiving, by a first load chamber of the first CVD apparatus, a tray bearing silicon wafers from a first loading level; (b) receiving the tray which is from the first loading cavity and bears the silicon wafer by a first transmission cavity of the first CVD equipment, and correspondingly conveying the tray to any available first CVD process cavity in a plurality of first CVD process cavities; (c) sequentially depositing a first amorphous silicon film selected from I/N type and I/P type amorphous silicon films on the first surface of the silicon wafer by the first CVD process cavity through a first intrinsic CVD process and an N-type or P-type doping CVD process, and correspondingly conveying the tray bearing the silicon wafer with the first surface subjected to deposition to the first transmission cavity; (d) receiving the tray loaded with the silicon wafer from the first CVD process chamber by the first transmission chamber, and correspondingly conveying the tray to a first unloading chamber of the first CVD equipment; (e) receiving the tray which comes from the first conveying cavity and bears the silicon wafers by the first unloading cavity, and conveying the tray to a first blanking position of the first CVD equipment so as to blank the silicon wafers from the tray; (f) receiving a blanked silicon wafer from a first blanking position of the first CVD equipment by a silicon wafer overturning device, overturning the silicon wafer to enable the first surface of the silicon wafer to be exchanged with a second surface opposite to the first surface, and conveying the overturned silicon wafer to a second loading position of the second CVD equipment for loading to a tray; (g) receiving, by a second load chamber of the second CVD apparatus, the tray from the second loading position and carrying the flipped silicon wafer; (h) receiving the tray loaded with the silicon wafer from the second loading cavity by a second transmission cavity of the second CVD equipment, and correspondingly conveying the tray to any available second CVD process cavity in a plurality of second CVD process cavities; (i) sequentially depositing a second amorphous silicon film selected from I/N type and I/P type amorphous silicon films on the second surface of the silicon wafer by the second CVD process cavity through a second intrinsic CVD process and a P type or N type doping CVD process, and correspondingly conveying the tray bearing the deposited silicon wafer to the second transmission cavity, wherein the second amorphous silicon film is different from the first amorphous silicon film; (j) receiving the tray loaded with the silicon wafer from the second CVD process chamber by the second transmission chamber, and conveying the tray to a second unloading chamber of the second CVD equipment; receiving the tray which comes from the second transmission cavity and bears the silicon wafers by the second unloading cavity, and conveying the tray to a blanking position so as to blank the silicon wafers from the tray.

The invention also provides the 17 th technical means of the plating method according to the 16 th technical means, wherein the step (c) comprises the following steps: (c1) heating the silicon wafer to a preset film forming temperature by the first CVD process chamber; (c2) providing a gas required for performing the first intrinsic CVD process from the first CVD process chamber and decomposing it using PECVD plasma or thermally dissociating it using HWCVD, thereby depositing a type I amorphous silicon thin film on the first side of the silicon wafer; providing a gas required for the N-type or P-type doping CVD process from the first CVD process chamber and decomposing it using PECVD plasma or thermally dissociating it using HWCVD, thereby depositing the first amorphous silicon thin film selected from the N-type and P-type amorphous silicon thin films on the first side; wherein the preset film-forming temperature of the silicon wafer is within the range of 100-300 ℃, the gas required for performing the first intrinsic CVD process in the step (c2) comprises silane or silane and hydrogen, the gas required for performing the N-type doped CVD process in the step (c3) comprises silane or silane and hydrogen, and further comprises phosphane, and the gas required for performing the P-type doped CVD process comprises silane or silane and hydrogen, and further comprises diborane or trimethylboron.

The invention also provides an 18 th technical means of the plating method according to the 16 th technical means, wherein the step (i) comprises the steps of: (i1) heating the silicon wafer to the preset film forming temperature by the second CVD process chamber; (i2) providing a gas required for performing the second intrinsic CVD process from the second CVD process chamber and decomposing it using PECVD plasma or thermally dissociating it using HWCVD, thereby depositing a type I amorphous silicon thin film on the second side of the silicon wafer; providing a gas required for performing the P-type doping CVD process from the second CVD process chamber and decomposing it using PECVD plasma or thermally dissociating it using HWCVD, thereby depositing the second amorphous silicon thin film selected from the N-type and P-type amorphous silicon thin films on the second face; wherein the preset film-forming temperature of the silicon wafer is within the range of 100-300 ℃, the gas required for performing the second intrinsic CVD process in the step (i2) comprises silane or silane and hydrogen, the gas required for performing the N-type doped CVD process in the step (i3) comprises silane or silane and hydrogen, and further comprises phosphane, and the gas required for performing the P-type doped CVD process comprises silane or silane and hydrogen, and further comprises diborane or trimethylboron.

The invention also provides a 19 th technical means of the plating method according to the 16 th technical means, wherein the method further comprises the following steps before the step (a): (a0) placing the silicon wafer into a tray at a first loading position of the first CVD apparatus.

The invention also provides the 20 th technical solution of the plating method according to the 16 th technical solution, wherein the method further comprises the following steps before the step (g): (g0) placing the flipped wafer into a tray at a second loading position of the second CVD apparatus.

The present invention also provides the 21 st aspect of the plating method according to the 16 th aspect, wherein the method further comprises, at the steps (e) and (f): (e1) receiving the tray loaded with the silicon wafers from the first unloading cavity at a first unloading position of the first CVD device, and taking the silicon wafers out of the tray to obtain an empty tray; (e2) returning, by a first tray return device of the first CVD apparatus, the empty tray from the first lower level to the first upper level.

The invention also provides the 22 nd technical means of the plating method according to the 16 th technical means, wherein the method further comprises, after the step (k): (k1) receiving the tray loaded with the silicon wafers from the second unloading cavity at a second unloading position of the second CVD equipment, and taking the silicon wafers out of the tray to obtain an empty tray; (k2) returning, by a second tray return device of the second CVD apparatus, the empty tray from the second blanking level to the second loading level.

Compared with the prior art, the invention has the following beneficial effects: according to the CVD equipment and the film coating method, the first CVD process cavity and the second CVD process cavity are used for depositing different first amorphous silicon films and second amorphous silicon films selected from I/N type amorphous silicon films and I/P type amorphous silicon films on the first surface and the second surface of the silicon wafer in sequence, so that 4 CVD process cavities for depositing the I/N/I/P type amorphous silicon films can be avoided being respectively configured, in addition, all the multiple layers of cavities are vertically stacked and integrally constructed into all the cavities in a vertical row, the integration level of the equipment is effectively improved, the occupied area is reduced, automatic equipment is reduced, the silicon wafer transmission link is reduced, the productivity and the yield are greatly improved, the equipment competitiveness is improved, and the first CVD process cavity or the second CVD process cavity for depositing the I/P type amorphous silicon films can effectively prevent cross contamination caused by boron through a boron removal process; the CVD equipment can also preheat the silicon wafer through the loading cavity, and can avoid the preheating in the first CVD process cavity and the second CVD process cavity for too long time, thereby effectively shortening the time of the silicon wafer staying in the first CVD process cavity and effectively improving the efficiency and the productivity of the CVD equipment.

Drawings

The above features and advantages of the present disclosure will be better understood upon reading the detailed description of embodiments of the disclosure in conjunction with the following drawings. In the drawings, components are not necessarily drawn to scale, and components having similar relative characteristics or features may have the same or similar reference numerals.

FIG. 1 is a schematic structural diagram of a CVD apparatus for fabricating a heterojunction solar cell according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of the structure of an embodiment of the CVD apparatus set for fabricating a heterojunction solar cell of the present invention;

FIG. 3 is a flow chart of a first embodiment of the coating method of the CVD apparatus set for manufacturing a heterojunction solar cell of the present invention;

fig. 4 is a flow chart of a second embodiment of the coating method of the CVD kit for manufacturing a heterojunction solar cell according to the invention.

Detailed description of the preferred embodiments

The invention will be described in detail below with reference to the accompanying drawings and specific embodiments so that the objects, features and advantages of the invention can be more clearly understood. It should be understood that the aspects described below in connection with the figures and the specific embodiments are exemplary only, and should not be construed as limiting the scope of the invention in any way. The singular forms "a", "an" and "the" include plural referents unless the context clearly dictates otherwise. As used in this specification and the appended claims, the terms "first," "second," and the like do not denote any order, quantity, or importance, but rather are used to distinguish one element from another.

As used in the specification and claims, the "I/P type amorphous silicon thin film" and the "I/N type amorphous silicon thin film" do not mean the "I type or P type amorphous silicon thin film" or the "I type or N type amorphous silicon thin film", but mean the "I type and P type amorphous silicon thin film" or the "I type and N type amorphous silicon thin film".

Referring to fig. 1, which shows a schematic structural diagram of an embodiment of the CVD apparatus for manufacturing a heterojunction solar cell of the present invention, the CVD apparatus 1 includes a loading position 10, a loading chamber 11, a transferring chamber 12, a plurality of CVD process chambers 14, an unloading chamber 16, and a unloading position 17, the transferring chamber 12 is located in a middle region of the CVD apparatus 1, the loading chamber 11, the plurality of CVD process chambers 14, and the unloading chamber 16 are connected to the transferring chamber 12 and are arranged around the transferring chamber 12, and relative positions of the loading chamber 11, the plurality of CVD process chambers 14, and the unloading chamber 16 can be changed according to requirements. The CVD apparatus 1 may be a PECVD apparatus, a HWCVD apparatus, or the like.

The CVD apparatus 1 further comprises a transfer device (mostly disposed in the transfer chamber 12) for transferring silicon wafers to and from the chambers, a loading device for placing silicon wafers from the flower basket into corresponding brackets of the tray at the loading position 10, and a unloading device for taking silicon wafers from the tray and transferring them to the flower basket at the unloading position 17, which may specifically include various transfer devices, loading devices and unloading devices commonly used in the art today or developed in the future, and for simplicity of illustration and description, the various transfer devices or mechanisms of silicon wafers will not be described in detail herein. In the present invention, the transfer chamber 12 is used as a transfer hub for the silicon wafer-carrying tray of the CVD apparatus 1, and the tray needs to be frequently transferred into and out of the transfer chamber 12 by frequently interacting with other chambers, so that more transfer devices can be disposed in the transfer chamber 12 than in other chambers.

The CVD equipment 1 can comprise a single-layer equipment unit and a multi-layer equipment unit, wherein the composition structure of the single-layer equipment unit is exemplarily shown in FIG. 1, and the single-layer equipment unit comprises a loading position 10, a loading cavity 11, a transmission cavity 12, a plurality of CVD process cavities 14, an unloading cavity 16 and a blanking position 17 which are positioned in the same horizontal layer. The multi-layer device unit comprises a plurality of single-layer device units correspondingly stacked in the vertical direction, and specifically, the number of single-layer device units can be 5, 10, 15, 20, 30, and the like, which can be thought and implemented by those skilled in the art. The multiple layers of loading cavities in the multilayer equipment unit are integrally constructed into a loading cavity vertical column, the multiple layers of conveying cavities in the multilayer equipment unit are integrally constructed into a conveying cavity vertical column, the multiple layers of CVD process cavities in the multilayer equipment unit are integrally constructed into a plurality of CVD process cavity vertical columns, and the multiple layers of unloading cavities in the multilayer equipment unit are integrally constructed into an unloading cavity vertical column; when the CVD equipment 1 is a multilayer equipment unit, the equipment integration level can be effectively improved, the occupied area is reduced, and the corresponding conveying device, the feeding device and the discharging device can be integrated and synchronously operated.

The CVD apparatus 1 may further comprise a tray return device (not shown) for transferring empty trays at the lower level 17 from the lower level 17 to the upper level 10, which may comprise a tray buffer for buffering trays. The tray buffer also optionally has a function for preheating the tray.

Referring to fig. 1, a loading chamber 11 is used for receiving a tray carrying silicon wafers from a loading station 10, and a preheating module (not shown) is further disposed in the loading chamber 11 and is used for preheating the silicon wafers to a temperature in the range of 25-250 ℃ before the silicon wafers enter any

available process chamber

141, 142, … 14m, …, or 14n of the plurality of CVD process chambers 14. The preheating module of the loading chamber 11 may be heated by contact heating and/or radiation heating, and may be embodied as an infrared heater, a thermal resistance heater, a high frequency heater, or the like, and may preheat the silicon wafer to a temperature in the range of 25-250 ℃ for a preheating time in the range of 10-500 seconds.

The transfer chamber 12 is configured to receive the tray loaded with the silicon wafer from the loading chamber 11 and correspondingly transfer the tray to any available

CVD process chamber

141, 142, … 14m, …, or 14n of the plurality of CVD process chambers 14, and the transfer chamber 12 is further configured to receive the tray loaded with the silicon wafer having completed the corresponding deposition process from any

CVD process chamber

141, 142, … 14m, …, or 14n of the plurality of CVD process chambers 14 and correspondingly transfer the tray to the unloading chamber 16. The transfer chamber 12 may be square, pentagonal, hexagonal or circular in shape or another shape suitable for transferring with other chambers. In the non-limiting embodiment shown in fig. 1, the transfer chamber 12 is circular in shape.

The plurality of CVD process chambers 14 are each configured to receive the tray loaded with the silicon wafer received and transferred from the load chamber 11 by the transfer chamber 12, and to sequentially deposit an I/N type or I/P type amorphous silicon thin film on one side of the silicon wafer by each of an intrinsic CVD process and a dopant CVD process. The plurality of CVD process chambers 14 are each configured to heat the wafer to a predetermined film formation temperature, which may be in a hydrogen-containing atmosphere. The plurality of CVD process chambers 14 are each further configured to: providing gas required for the intrinsic CVD process and decomposing the gas by using PECVD plasma or thermally dissociating the gas by using HWCVD so as to deposit an I-type amorphous silicon film on one side of the silicon wafer; and providing gas required for the doping CVD process, decomposing the gas by using PECVD plasma or thermally dissociating the gas by using HWCVD, thereby depositing the N-type or P-type amorphous silicon film on the I-type amorphous silicon film and forming the I/N-type or I/P-type amorphous silicon film.

The preset film forming temperature of the silicon wafer is within the range of 100-300 ℃, and the gas required by the intrinsic CVD process comprises silane or silane and hydrogen; the doping CVD process comprises an N-type doping CVD process and a P-type doping CVD process, wherein gases required by the N-type doping CVD process comprise silane or silane and hydrogen, and also comprise phosphine or other gases suitable for N-type doping; the gases required to perform the P-type doping CVD process include silane or silane and hydrogen, and further include diborane or trimethylboron or other gases suitable for P-type doping. In one embodiment, the intrinsic CVD process and the doped CVD process are both performed at 100-300 ℃.

The CVD apparatus 1 includes a plurality of CVD process chambers 14, which may specifically include two, three, four, or n (e.g., six) CVD process chambers greater than four, and the number of CVD process chambers may be determined comprehensively according to the conveying capacity of the transfer chamber 12, the processing capacity of the CVD apparatus, and other factors. In one embodiment, the CVD apparatus 1 includes two CVD process chambers 14, the transfer chamber 12 may be disposed in a square shape, and the loading chamber 11, the two CVD process chambers 14, and the unloading chamber 16 surround the square transfer chamber 12 and are disposed on four sides of the square. In one embodiment, the CVD apparatus 1 includes three CVD process chambers, the transfer chamber 12 may be disposed in a pentagon, and the loading chamber 11, the three CVD process chambers 14 and the unloading chamber 16 respectively surround the pentagon of the transfer chamber 12 and are disposed on five sides of the pentagon.

The plurality of CVD process chambers 14 also have a cleaning function that can clean the chambers themselves and empty trays that enter them.

The unloading chamber 16 is used for receiving the tray which is loaded with the silicon wafers which are finished with the intrinsic CVD process and the doping CVD process from the transmission chamber 12 and transferring the tray to a blanking position 17 so as to blank the silicon wafers from the tray.

Although one CVD process chamber 14n is shown between the load chamber 11 and the unload chamber 16 in fig. 1, in other embodiments, a plurality of CVD process chambers may be disposed between the load chamber 11 and the unload chamber 16, or none of the CVD process chambers may be disposed.

Referring to fig. 2, there is shown the composition of an embodiment of the CVD kit of parts for manufacturing a heterojunction solar cell of the invention. The complete set of CVD equipment comprises a first CVD equipment 2, a second CVD equipment 3 and a silicon wafer turnover device 4 which are sequentially connected, wherein the first CVD equipment 2 and the second CVD equipment 3 are used for respectively depositing a first amorphous silicon film selected from I/N type and I/P type amorphous silicon films and a second amorphous silicon film different from the first amorphous silicon film on the first surface and the second surface of the silicon wafer. The structure and operation principle and process of the components of the first CVD apparatus 2 and the second CVD apparatus 3 are substantially the same as those of the CVD apparatus 1 shown in fig. 1 and described above, and for the specific embodiment thereof, the first CVD apparatus 2 and the second CVD apparatus 3 can be understood with reference to the CVD apparatus 1 shown in fig. 1 and described above. The first CVD apparatus 2 includes a first loading level 20, a first loading chamber 21, a first transfer chamber 22, a plurality of first CVD process chambers 24 and a first unloading chamber 26, a first unloading level 27. The second CVD apparatus 3 includes a second loading level 30, a second loading chamber 31, a second transfer chamber 32, a plurality of second CVD process chambers 34, a second unloading chamber 36 and a second unloading level 37. The first CVD apparatus 2 further comprises tray return means for conveying the empty trays from a first lower level 27 to the first upper level 20, and the second CVD apparatus 3 further comprises tray return means for conveying the empty trays from a second lower level 37 to the upper level 30.

The first CVD apparatus 2 and the second CVD apparatus 3 each include a PECVD apparatus and a HWCVD apparatus, and the first and

second loading chambers

21 and 31 may each be provided with a preheating module for preheating the silicon wafer to a temperature in the range of 25-250 c before the silicon wafer enters any one of the available first

CVD process chambers

241, 242, … 24m, …, or 24n or second

CVD process chambers

341, 342, … 34m, …, or 34 n.

The CVD apparatus set includes a single-layer set unit or a multi-layer set unit, and as shown in fig. 2, the single-layer set unit includes a first CVD apparatus 2, a second CVD apparatus 3, and a wafer reversing device 4, which are located substantially in the same horizontal layer. The multi-layer plant unit comprises a plurality of single-layer plant units correspondingly stacked in the vertical direction, and specifically, the multi-layer plant unit can comprise 5, 10, 15, 20, 30 single-layer plant units and the like, which are conceivable and practicable by those skilled in the art. The multilayer first loading cavity 21, the multilayer first transmission cavity 22, the multilayer multiple first CVD process cavities 24, the multilayer first unloading cavity 26, the multilayer second loading cavity 31, the multilayer second transmission cavity 32, the multilayer multiple second CVD process cavities 34 and the multilayer second unloading cavity 36 in the multilayer complete equipment unit can be respectively and integrally constructed into a first loading cavity vertical column, a first transmission cavity vertical column, a plurality of first CVD process cavity vertical columns, a first unloading cavity vertical column, a second loading cavity vertical column, a second transmission cavity vertical column, a plurality of second CVD process cavity vertical columns and a second unloading cavity vertical column.

The plurality of first CVD process chambers 24 of the first CVD apparatus 2 of fig. 2 are used to sequentially deposit a first amorphous silicon thin film selected from the group consisting of I/N type and I/P type amorphous silicon thin films on the first side of the silicon wafer through a first intrinsic CVD process and an N type or P type doping CVD process, and the plurality of second CVD process chambers 34 of the second CVD apparatus 3 of fig. 2 are used to sequentially deposit a second amorphous silicon thin film different from the first amorphous silicon thin film selected from the group consisting of I/N type and I/P type amorphous silicon thin films on the second side of the silicon wafer through a second intrinsic CVD process and a P type or N type doping CVD process.

In the first embodiment of the kit, the first and second amorphous silicon films are I/N type and I/P type amorphous silicon films, respectively, each of the plurality of first CVD process chambers 24 sequentially deposits an I/N type amorphous silicon film on the first side of the silicon wafer through a first intrinsic CVD process and an N type doping CVD process, and each of the plurality of second CVD process chambers 34 of the second CVD apparatus 3 of fig. 2 sequentially deposits an I/P type amorphous silicon film on the second side of the silicon wafer through a second intrinsic CVD process and a P type doping CVD process.

In the second embodiment of the kit, the first and second amorphous silicon films are I/P type and I/N type amorphous silicon films, respectively, each CVD process chamber of the plurality of first CVD process chambers 24 sequentially deposits the I/P type amorphous silicon film on the first side of the silicon wafer through the first intrinsic CVD process and the P type doping CVD process, and each CVD process chamber of the plurality of second CVD process chambers 34 of the second CVD apparatus 3 of fig. 2 sequentially deposits the I/N type amorphous silicon film on the second side of the silicon wafer through the second intrinsic CVD process and the N type doping CVD process.

Each of the first

CVD process chambers

241, 242, … 24m, …, or 24n is configured to heat the silicon wafer to a predetermined film formation temperature, which may be in a hydrogen-containing atmosphere. Each of the second

CVD process chambers

341, 342, … 34m, …, or 34n is configured to heat the silicon wafer to the preset film formation temperature, which may be performed in a hydrogen-containing atmosphere.

Each of the first

CVD process chambers

241, 242, … 24m, …, or 24N or each of the second

CVD process chambers

341, 342, … 34m, …, or 34N depositing the I/N type amorphous silicon thin film is further configured to: and providing gas required for performing the first or second intrinsic CVD process and decomposing the gas by using PECVD plasma or thermally dissociating the gas by using HWCVD to deposit the I-type amorphous silicon thin film on the first surface of the silicon wafer, and providing gas required for performing the N-type doping CVD process and decomposing the gas by using PECVD plasma or thermally dissociating the gas by using HWCVD to deposit the N-type amorphous silicon thin film on the first surface of the silicon wafer and form the I/N-type amorphous silicon thin film. The preset film forming temperature of the silicon wafer is within the range of 100-300 ℃, the gas required for performing the first or second intrinsic CVD process comprises silane or silane and hydrogen, the gas required for performing the N-type doping CVD process comprises silane or silane and hydrogen, and further comprises phosphine or other gases suitable for performing N-type doping. The first or second intrinsic CVD process and the N-type doped CVD process are both performed within a range of 100-300 ℃.

In the first embodiment of the kit, each of the first

CVD process chambers

241, 242, … 24m, …, or 24N is used for depositing an I/N type amorphous silicon thin film. In the second embodiment of the kit, each of the second

CVD process chambers

341, 342, … 34m, …, or 34N is used for depositing an I/N type amorphous silicon thin film.

Each of the first

CVD process chambers

241, 242, … 24m, …, or 24n or each of the second

CVD process chambers

341, 342, … 34m, …, or 34n depositing the I/P type amorphous silicon thin film is further configured to: providing a gas required for performing the first or second intrinsic CVD process and decomposing it using PECVD plasma or thermally dissociating it using HWCVD, thereby depositing a type I amorphous silicon thin film on the second face; and providing gas required for carrying out a P-type doping CVD process, decomposing the gas by utilizing PECVD plasma or thermally dissociating the gas by utilizing HWCVD so as to deposit a P-type amorphous silicon film on the second surface and form the I/P-type amorphous silicon film. The preset film forming temperature of the silicon wafer is within the range of 100-300 ℃, the gas required for carrying out the first or second intrinsic CVD process comprises silane or silane and hydrogen, the gas required for carrying out the P-type doping CVD process comprises silane or silane and hydrogen, and further comprises diborane or trimethylboron or other gases suitable for carrying out P-type doping. The first or second intrinsic CVD process and the P-type doped CVD process are both performed within the range of 100-300 ℃. In the first embodiment of the kit, each of the second

CVD process chambers

341, 342, … 34m, …, or 34n is used for depositing an I/P type amorphous silicon thin film. In the second embodiment of the kit, each of the first

CVD process chambers

241, 242, … 24m, …, or 24n is used to deposit an I/P type amorphous silicon thin film.

The wafer reversing device 4 is configured to receive the silicon wafer which is completely discharged at the first discharging position 27 from the first discharging chamber 26 of the first CVD apparatus 2, and to reverse the silicon wafer so that the first side of the silicon wafer is exchanged with the second side opposite to the first side. The silicon wafer overturning device 4 can be a device for integrally overturning the silicon wafer once, a device for overturning the silicon wafer in a multi-step rotating manner, and other silicon wafer overturning devices which can be thought of by those skilled in the art or developed in the future.

It should be noted that the second intrinsic CVD process performed in the second CVD process chamber 34 may be identical to the first intrinsic CVD process performed in the first CVD process chamber 24, or the second intrinsic CVD process may be different from the first intrinsic CVD process, and the two processes may have differences in parameters such as specific process gas components, process gas flow rates, process time, and process temperature.

Each of the first

CVD process chamber

241, 242, … 24m, …, or 24n and the second

CVD process chamber

341, 342, … 34m, …, or 34n further has a pair of chambersThe body and the cleaning function of cleaning the empty tray entering the body can also carry out the pre-coating process on the empty tray. The pre-coating process is used for depositing the amorphous silicon thin film on the surface of the tray, so that any pollution of the tray to the heterojunction solar cell is avoided. The cleaning gas corresponding to the cleaning function comprises NF₃、C₂F₆、CF₄、CHF₃、SF₆、F₂、HF、Ar、Cl₂And HCl, or any combination thereof. The plurality of first CVD process chambers 24 and the plurality of second CVD process chambers 34 may be used to perform a pre-coating process or a cleaning process of the trays without sending a part of the trays processed by the cleaning function to a tray pre-coating/cleaning device outside the plant.

After the first CVD process chambers 24 or the second CVD process chambers 34 complete the I/P type amorphous silicon thin films of a certain number or batch of silicon wafers, a boron removal process may be performed before the film formation of the next batch of silicon wafers, so as to provide a cleaner first CVD process chambers 24 or second CVD process chambers 34 for the next batch of silicon wafers to deposit the I/P type amorphous silicon thin films therein. The boron removal process is effective to eliminate cross-contamination between different process cycles of the plurality of first CVD process chambers 24 or second CVD process chambers 34.

In some embodiments, the first CVD apparatus 2 and the second CVD apparatus 3 are PECVD apparatuses, and the corresponding plurality of first CVD process chambers 24 and the plurality of second CVD process chambers 34 can deposit different first and second amorphous silicon thin films selected from I/N and I/P type amorphous silicon thin films, respectively, by low frequency dissociation, high frequency dissociation, very high frequency dissociation, ultra high frequency dissociation, or microwave dissociation of the process gases and by plasma ignition. In other embodiments, the first CVD apparatus 2 and the second CVD apparatus 3 are HWCVD apparatuses, and the corresponding plurality of first CVD process chambers 24 and the corresponding plurality of second CVD process chambers 34 may deposit different first and second amorphous silicon films selected from I/N and I/P type amorphous silicon films by inducing dissociation of the process gases by hot wire dissociation.

As shown in FIG. 2, the silicon wafers are flowed along a flow path composed of a first loading position 20, a first loading chamber 21, a first transfer chamber 22, any available first CVD process chamber 24, a first transfer chamber 22, a first unloading chamber 26, a first unloading position 27, a silicon wafer turning device 4, a second loading position 30, a second loading chamber 31, a second transfer chamber 32, any available second CVD process chamber 34, a second transfer chamber 32, a second unloading chamber 36, and a second unloading position 37, while the tray for carrying the silicon wafers is flowed along a flow path composed of a first loading position 20, a first loading chamber 21, a first transfer chamber 22, any available first CVD process chamber 24, a first transfer chamber 22, a first unloading chamber 26, a first unloading position 27, a tray transfer device, and a first loading position 20 in the first CVD apparatus 2, while the tray for carrying the silicon wafers is flowed along a flow path composed of a second loading position 30, a second unloading position 27, a second unloading position 37, and a second unloading position 37, The second loading chamber 31, the second transfer chamber 32, any available second CVD process chamber 34, the second transfer chamber 32, the second unloading chamber 36, the second discharge level 37, the tray transfer device, and the second loading level 30.

In other embodiments, the silicon wafer may be sequentially circulated along the second CVD apparatus 3, the silicon wafer turning device 4, and the first CVD apparatus 2 in substantially the same way and manner as described above.

Referring to fig. 3, in combination with fig. 1 and 2, fig. 3 shows a flow chart of a first embodiment of the coating method of the CVD kit for manufacturing a heterojunction solar cell according to the invention. The complete set of CVD equipment comprises a first CVD equipment 2, a second CVD equipment 3 and a silicon wafer overturning device 4, and the detailed structure, characteristics and operation of each component of the first CVD equipment 2, the second CVD equipment 3 and the silicon wafer overturning device 4 can be understood by referring to the above and the figures 1 and 2. The complete set of CVD equipment comprises PECVD complete set, HWCVD complete set and the like.

The method 40 of the first embodiment shown in FIG. 3 includes a step S300 of placing silicon wafers into a tray at the first loading level 20 of the first CVD apparatus 2. In some embodiments, which may include the first embodiment, the wafers are placed by the loading device at the first loading position 20 into a tray, which may be a square tray with 8 by 8 wafers and 64 wafers, or a rectangular tray with other quantities of wafers, and the tray size may be set and adjusted as desired or the cavity size.

The method 40 further includes a step S310 of receiving a tray carrying silicon wafers from the first loading level 20 by the first loading chamber 21 of the first CVD apparatus 2. In step S310, the tray carrying the silicon wafer may be received into the first loading chamber 21 by a transfer device commonly used in the art, such as a robot arm or a roller or a belt.

The method 40 further includes a step S320 of preheating the silicon wafer to a temperature in the range of 25 to 250 ℃ in the first load chamber 21, and transferring the tray carrying the silicon wafer to the first transfer chamber 22 of the first CVD apparatus 2. In some embodiments, which may include the first embodiment, the wafer is preheated to a temperature in the range of 25-250 c over a preheating time in the range of 10-500 seconds. In still other embodiments, which may include the first embodiment, the wafer is preheated to a temperature in the range of 40-200 c over a preheating time in the range of 10-500 seconds. In step S310, the tray carrying the silicon wafer may be transferred to the first transfer chamber 22 by a transfer device commonly used in the art, such as a robot arm or a roller or a belt.

The method 40 further includes step S330, receiving the tray loaded with the silicon wafer from the first loading chamber 21 by the first transfer chamber 22, and correspondingly transferring the tray to any available first CVD process chamber in the plurality of first CVD process chambers 14. In step S330, the tray carrying the silicon wafer may be received into the first transfer chamber 22 by a conveying device commonly used in the art, such as a robot arm, a roller, a belt, etc., and may also be conveyed into any available first CVD process chamber by a corresponding robot arm, a roller, a belt, etc.; the plurality of first CVD process chambers 24 of the first CVD apparatus 2 may be designed to be idle when needed, but there is no case where the first CVD process chambers 24 are idle for a long time.

The method 40 further includes step S340, heating the silicon wafer to a preset film forming temperature by the first CVD process chamber. In some embodiments, which may include the first embodiment, the step S340 is performed in a hydrogen-containing atmosphere, and the predetermined film-forming temperature of the silicon wafer is within the range of 100 ℃ to 300 ℃. The predetermined film formation temperature may more specifically be in the range of 150 ℃ -.

The method 40 further includes step S350 of providing a gas required for performing a first intrinsic CVD process from the first CVD process chamber and decomposing it using PECVD plasma or thermally dissociating it using HWCVD, thereby depositing a type I amorphous silicon thin film on the first side of the silicon wafer. In some embodiments, which may include the first embodiment, the gas required to perform the intrinsic CVD process in step S350 includes silane. In other embodiments, the gases required to perform the intrinsic CVD process in step S350 include silane and hydrogen.

The method 40 further includes step S360 of providing a gas required for the N-type doping CVD process from the first CVD process chamber and decomposing it using PECVD plasma or thermally dissociating it using HWCVD, thereby depositing the N-type amorphous silicon thin film and forming an I/N-type amorphous silicon thin film on the first surface. In some embodiments, which may include the first embodiment, the gases required to perform the N-type doping CVD process in step S360 include silane or silane and hydrogen, and also include phosphane or other gases suitable for N-type doping.

The method 40 further includes a step S370 of transferring the tray carrying the silicon wafer whose first surface has finished the I/N type amorphous silicon thin film deposition from the first CVD process chamber to the first transfer chamber 22. In step S370, the tray carrying the silicon wafer may be transferred to the first transfer chamber 22 by a transfer device commonly used in the art, such as a robot arm or a roller or a belt.

The method 40 further includes step S380, receiving the tray loaded with the silicon wafer from the first CVD process chamber by the first transfer chamber 22, and correspondingly transferring the tray to the first unloading chamber 26 of the first CVD apparatus 2. In step S380, the tray carrying the silicon wafer may be transferred to the first unloading chamber 26 by a transfer device commonly used in the art, such as a robot arm or a roller or a belt.

The method 40 further includes a step S390 of receiving the tray loaded with the silicon wafer from the first transfer chamber 22 by the first unloading chamber 26 and transferring the tray to a first unloading position 27 of the first CVD apparatus 2. In step S390, the tray carrying the silicon wafer may be transferred to the first unloading position 27 by a transfer device commonly used in the art, such as a robot arm or a roller or a belt.

The method 40 further includes a step S400 of receiving the blanked silicon wafer from the first blanking position 27 by the silicon wafer flipping device 4, flipping the silicon wafer to exchange the first surface of the silicon wafer with the second surface opposite to the first surface, and transferring the flipped silicon wafer to the second loading position 30 of the second CVD apparatus 3 to be loaded to a tray. In some embodiments, which may include the first embodiment, the wafer flipping apparatus 4 may perform the wafer flipping in step S400 by flipping 180 degrees at a time. In step S400, the tray carrying the silicon wafers may be transferred to the second loading position 30 by a transfer device commonly used in the art, such as a robot arm or a roller or a belt.

The method 40 further includes a step S410 of receiving, by the second loading chamber 31 of the second CVD apparatus 3, the tray loaded with the flipped silicon wafer from the second loading position 30. In step S410, the tray carrying the silicon wafer may be received into the second loading chamber 31 by a transfer device commonly used in the art, such as a robot arm or a roller or a belt.

The method 40 further includes a step S420 of preheating the silicon wafer to a temperature in the range of 25 to 250 ℃ by the second loading chamber 31, and transferring the tray on which the silicon wafer is loaded to the second transfer chamber 32 of the second CVD apparatus 3. In some embodiments, which may include the first embodiment, the wafer is preheated to a temperature in the range of 25-250 c over a preheating time in the range of 10-500 seconds. In step S420, the tray carrying the silicon wafer may be transferred to the second transfer chamber 32 by a transfer device commonly used in the art, such as a robot arm or a roller or a belt.

The method 40 further includes step S430, receiving the tray loaded with the silicon wafer from the second loading chamber 31 by the second transfer chamber 32, and correspondingly transferring the tray to any available second CVD process chamber in the plurality of second CVD process chambers 34. In step S430, the tray may be received into the second transfer chamber 32 by a transfer device commonly used in the art, such as a robot arm or a roller or a belt, and the tray carrying the silicon wafer may be transferred to any available second CVD process chamber by a transfer device commonly used in the art, such as a robot arm or a roller. The plurality of second CVD process chambers 34 of the second CVD apparatus 3 may be preferably designed to be idle when needed, but there is no case where the second CVD process chambers 34 are idle for a long time.

The method 40 further includes step S440, heating the silicon wafer to the preset film forming temperature by the second CVD process chamber. In one embodiment, the step S440 is performed in a hydrogen-containing atmosphere, and the predetermined film forming temperature is within the range of 100 ℃ to 300 ℃.

The method 40 further includes step S450 of depositing a type I amorphous silicon thin film on the second side of the silicon wafer by supplying a gas required for performing a second intrinsic CVD process from the second CVD process chamber and decomposing it using PECVD plasma or thermally dissociating it using HWCVD. The gas required for the intrinsic CVD process in step S450 includes silane and may also include a certain amount of hydrogen. In some embodiments, which may include the first embodiment, the second intrinsic CVD process in step S450 may be identical to the first intrinsic CVD process in step S350. In other embodiments, the second intrinsic CVD process in step S450 and the first intrinsic CVD process in step S350 may be different, and both may differ in specific process gas composition, gas flow rate, process time, process temperature, etc.

The method 40 further includes step S460 of providing a gas required for the P-type doping CVD process from the second CVD process chamber and decomposing it using PECVD plasma or thermally dissociating it using HWCVD, thereby depositing the P-type amorphous silicon thin film and forming an I/P-type amorphous silicon thin film on the second face. The gas required for performing the P-type doping CVD process in step S460 includes silane or silane and hydrogen, and further includes diborane or trimethylboron or other gas suitable for performing P-type doping.

The method 40 further includes a step S470 of transferring the tray carrying the silicon wafer whose first surface has finished the I/P type amorphous silicon thin film deposition to the second transfer chamber 32 by the second CVD process chamber. In step S470, the tray carrying the silicon wafer may be transferred to the second transfer chamber 32 by a transfer device commonly used in the art, such as a robot arm or a roller or a belt.

The method 40 further includes step S480 of receiving the tray loaded with the silicon wafer from the second CVD process chamber by the second transfer chamber 32, and transferring the tray to a second unloading chamber 36 of the second CVD apparatus. In step S480, the tray carrying the silicon wafer may be transferred to the second unloading chamber 36 by a transfer device commonly used in the art, such as a robot arm or a roller or a belt.

The method 40 further includes a step S490 of receiving the tray loaded with the silicon wafer from the second transfer chamber by the second unloading chamber 36 and transferring the tray to a second unloading position 37 to unload the silicon wafer from the tray. In step S490, the tray carrying the silicon wafer may be transferred to the discharging position 37 by a transfer device commonly used in the art, such as a robot arm or a roller or a belt.

The method 40 may further perform the following steps after step S390: receiving the tray loaded with the silicon wafers from the first unloading chamber 26 at a first unloading position 27 of the first CVD apparatus and taking out the silicon wafers from the tray to obtain an empty tray; the empty trays are returned from the first lower level 27 to the first upper level 20 by a first tray return means of the first CVD apparatus.

The method 40 may further perform the following steps after step S490: receiving the tray loaded with the silicon wafer from the second unloading chamber 36 at a second blanking position 37 of the second CVD apparatus, and taking out the silicon wafer from the tray to obtain an empty tray; the empty trays are returned from the second blanking level 37 to the second loading level 30 by a second tray return means of the second CVD apparatus.

The method 40 may further include cleaning the chamber itself and the empty trays introduced therein in the plurality of first and second CVD process chambers 24 and 34, respectively, by having a cleaning function that may be scheduled for periodic use or scheduled for use in terms of the number of plating performed or an estimated film thickness.

The method 40 may further include a boron removal process performed after the second CVD process chamber 34 has completed the I/P type amorphous silicon thin film for a number or batch of wafers, thereby providing a cleaner second CVD process chamber 34 for the next batch of wafers to deposit the I/P type amorphous silicon thin film therein. The boron removal process is effective to eliminate cross-contamination between different process cycles of the second CVD process chamber 34.

Fig. 4 shows a flow chart of a second exemplary embodiment of a coating method according to the invention for a CVD kit for producing a heterojunction solar cell, the coating method 40 "being substantially identical to the coating method 40 in respect of steps, for example steps S300 to S340, S380 to S440, S480 to S490 in the coating method 40 are substantially identical to steps S300" -S340 ", S380" -S440 ", S480" -S490 "in the coating method 40".

The greatest difference between the coating methods 40 and 40 'is that the method 40 firstly performs steps S350 and S360 to form an I/N type amorphous silicon thin film on the first surface of the silicon wafer, and then performs steps S450 and S460 to form an I/P type amorphous silicon thin film on the second surface of the silicon wafer, while the method 40' firstly performs steps S350 'and S360' to form an I/P type amorphous silicon thin film on the first surface of the silicon wafer, and then performs steps S450 'and S460' to form an I/N type amorphous silicon thin film on the second surface of the silicon wafer; the subsequent steps S370 and S370 ″ corresponding thereto are to perform I/N type and I/P type amorphous silicon thin film deposition, respectively, on the first side of the silicon wafer carried by the tray transferred to the first transfer chamber 22, and the subsequent steps S470 and S470 ″ are to perform I/P type and I/N type amorphous silicon thin film deposition, respectively, on the second side of the silicon wafer carried by the tray transferred to the second transfer chamber 32. For simplicity of illustration, the method 40 "may be understood with reference to the description above for the method 40.

The single coating method of the CVD apparatus for manufacturing the heterojunction solar cell in fig. 1 can be performed with reference to steps S300 to S390 or S410 to S490 in the method 40 in fig. 3, and for simplicity of illustration and description, the detailed description thereof is omitted.

According to the CVD equipment and the film coating method, the first CVD process cavity and the second CVD process cavity are used for respectively depositing different first amorphous silicon films and second amorphous silicon films selected from I/N type amorphous silicon films and I/P type amorphous silicon films on the first surface and the second surface of the silicon wafer in sequence, 4 CVD process cavities can be prevented from being equipped for respectively depositing the I/N/I/P type amorphous silicon films, in addition, all the multiple layers of cavities are vertically stacked and integrally constructed into the vertical columns of all the cavities, so that the integration level of the equipment is effectively improved, the occupied area is reduced, automatic equipment is reduced, the silicon wafer transmission link is reduced, the productivity and the yield are greatly improved, the equipment competitiveness is improved, and the first CVD process cavity or the second CVD process cavity for depositing the I/P type amorphous silicon films can effectively prevent boron-related cross contamination through the boron removing device; the CVD equipment provided by the invention preheats the silicon wafer through the loading cavity, and can avoid the preheating in the first CVD process cavity and the second CVD process cavity for too long time, so that the time of the silicon wafer staying in the first CVD process cavity and the second CVD process cavity is effectively shortened, and the efficiency and the capacity of the CVD equipment can be effectively improved.

The embodiments described above are provided to enable persons skilled in the art to make or use the invention and that modifications or variations can be made to the embodiments described above by persons skilled in the art without departing from the inventive concept of the present invention, so that the scope of protection of the present invention is not limited by the embodiments described above but should be accorded the widest scope consistent with the innovative features set forth in the claims.

Claims

1. A CVD apparatus for fabricating a heterojunction solar cell, the CVD apparatus comprising:

a loading chamber configured to receive a tray carrying silicon wafers from a loading position;

a plurality of CVD process chambers configured to receive the tray loaded with the silicon wafer and to sequentially deposit an I/N type or I/P type amorphous silicon thin film on one side of the silicon wafer through an intrinsic CVD process and a doping CVD process, respectively;

an unloading chamber configured to receive the tray carrying the silicon wafers having completed the intrinsic CVD process and the impurity-doped CVD process and transfer them to a discharge position to discharge the silicon wafers from the tray; and

and the conveying cavity is connected with the loading cavity, the plurality of CVD process cavities and the unloading cavity and is configured to receive the tray which is loaded with the silicon wafer and comes from any one of the loading cavity or the plurality of CVD process cavities and correspondingly convey the tray to any available CVD process cavity or the unloading cavity.

2. The CVD apparatus of claim 1, wherein the CVD apparatus comprises a PECVD apparatus and a HWCVD apparatus, and the loading chamber is further provided with a preheating module configured to preheat the silicon wafer to a temperature in the range of 25-250 ℃ before the silicon wafer enters any available process chamber of the plurality of CVD process chambers; the plurality of CVD process chambers also have a cleaning function capable of cleaning the chambers themselves and the empty trays introduced therein.

3. The CVD apparatus of claim 1 or 2, wherein the plurality of CVD process chambers are each configured to: heating the silicon wafer to a preset film forming temperature, providing gas required by the intrinsic CVD process, decomposing the gas by utilizing PECVD plasma or thermally dissociating the gas by utilizing HWCVD so as to deposit an I-type amorphous silicon film on one surface of the silicon wafer; providing gas required for the doping CVD process and decomposing the gas by using PECVD plasma or thermally dissociating the gas by using HWCVD so as to deposit the N-type or P-type amorphous silicon film on the I-type amorphous silicon film and form an I/N-type or I/P-type amorphous silicon film; the preset film forming temperature of the silicon wafer is within the range of 100-300 ℃, the gas required by the intrinsic CVD process comprises silane or silane and hydrogen, and the gas required by the doped CVD process comprises silane or silane and hydrogen, and also comprises phosphine, diborane or trimethylboron.

4. The CVD apparatus according to claim 1 or 2, wherein the CVD apparatus comprises a single-layer apparatus unit and a multi-layer apparatus unit, the single-layer apparatus unit comprising the loading chamber, the transfer chamber, the plurality of CVD process chambers and the unloading chamber in the same horizontal layer; the multilayer equipment unit comprises a plurality of single-layer equipment units which are correspondingly stacked along the vertical direction, and the multilayer equipment unit comprises a multilayer loading cavity, a multilayer transmission cavity, a plurality of multilayer CVD process cavities and a plurality of multilayer unloading cavities which are respectively and correspondingly integrated into a loading cavity vertical column, a transmission cavity vertical column, a plurality of CVD process cavity vertical columns and an unloading cavity vertical column; the CVD apparatus further comprises a tray pass-back device configured to transfer an empty tray from the loading position to the unloading position, wherein the silicon wafer is placed into the tray at the loading position, and the silicon wafer is taken out of the tray at the unloading position to obtain the empty tray.

5. A CVD kit for fabricating a heterojunction solar cell for depositing a first amorphous silicon thin film selected from the group consisting of I/N type and I/P type amorphous silicon thin films and a second amorphous silicon thin film different from the first amorphous silicon thin film on a first side and a second side of a silicon wafer, respectively, the CVD kit comprising:

a first CVD apparatus according to any one of claims 1 to 4, the first CVD apparatus comprising a first loading chamber, a first transporting chamber, a plurality of first CVD process chambers and a first unloading chamber, each of the first CVD process chambers being configured to receive a tray carrying a silicon wafer and to deposit the first amorphous silicon thin film selected from the group consisting of I/N type and I/P type amorphous silicon thin films on the first side of the silicon wafer by a first intrinsic CVD process and an N-type or P-type doping CVD process in sequence;

a silicon wafer turning device configured to receive the silicon wafer, a first side of which has finished deposition and is blanked, from a first unloading chamber of the first CVD apparatus, and turn the silicon wafer so that the first side of the silicon wafer is exchanged with a second side opposite to the first side; and

a second CVD apparatus according to any one of claims 1 to 4, the second CVD apparatus being configured to receive the tray carrying the silicon wafer flipped over by the wafer flipping device, the second CVD apparatus comprising a second loading chamber, a second transporting chamber, a plurality of second CVD process chambers and a second unloading chamber, each of the second CVD process chambers being configured to receive the tray carrying the flipped-over silicon wafer and to sequentially deposit the second amorphous silicon thin film selected from the group consisting of I/N type and I/P type amorphous silicon thin films on the second side of the silicon wafer by a second intrinsic CVD process and a P-type or N-type doping CVD process.

6. The CVD tool set of claim 5, wherein the first CVD process chamber or the second CVD process chamber for depositing the I/N type amorphous silicon thin film is configured to: heating the silicon wafer to a preset film forming temperature, providing gas required by the first or second intrinsic CVD process, decomposing the gas by utilizing PECVD plasma or thermally dissociating the gas by utilizing HWCVD so as to deposit an I-type amorphous silicon film on the first surface of the silicon wafer; providing gas required for carrying out an N-type doping CVD process, decomposing the gas by utilizing PECVD plasma or thermally dissociating the gas by utilizing HWCVD so as to deposit an N-type amorphous silicon film on the first surface and form the I/N-type amorphous silicon film; wherein the preset film forming temperature of the silicon wafer is within the range of 100-300 ℃, the gas required for performing the first or second intrinsic CVD process comprises silane or silane and hydrogen, and the gas required for performing the N-type doped CVD process comprises silane or silane and hydrogen and also comprises phosphane.

7. The CVD tool set of claim 5, wherein the first CVD process chamber or the second CVD process chamber for depositing the I/P type amorphous silicon thin film is configured to: heating the silicon wafer to the preset film forming temperature, providing gas required by the first or second intrinsic CVD process, decomposing the gas by utilizing PECVD plasma or thermally dissociating the gas by utilizing HWCVD so as to deposit an I-type amorphous silicon film on the second surface of the silicon wafer; providing gas required for carrying out a P-type doping CVD process, decomposing the gas by utilizing PECVD plasma or thermally dissociating the gas by utilizing HWCVD so as to deposit a P-type amorphous silicon film on the second surface and form the I/P-type amorphous silicon film; wherein the preset film forming temperature of the silicon wafer is within the range of 100-300 ℃, the gas required for performing the first or second intrinsic CVD process comprises silane or silane and hydrogen, the gas required for performing the P-type doped CVD process comprises silane or silane and hydrogen, and further comprises diborane or trimethyl boron; the first CVD process chamber or the second CVD process chamber on which the I/P type amorphous silicon thin film is deposited is further configured to perform a boron removal device capable of removing boron contamination.

8. A coating method for a CVD apparatus kit for manufacturing a heterojunction solar cell, the CVD apparatus kit comprising a first CVD apparatus, a silicon wafer turning device and a second CVD apparatus, the method comprising the steps of:

(a) receiving, by a first load chamber of the first CVD apparatus, a tray bearing silicon wafers from a first loading level;

(b) receiving the tray which is from the first loading cavity and bears the silicon wafer by a first transmission cavity of the first CVD equipment, and correspondingly conveying the tray to any available first CVD process cavity in a plurality of first CVD process cavities;

(c) sequentially depositing a first amorphous silicon film selected from I/N type and I/P amorphous silicon films on the first surface of the silicon wafer by the first CVD process cavity through a first intrinsic CVD process and an N-type or P-type doping CVD process, and correspondingly conveying the tray bearing the silicon wafer with the first surface subjected to deposition to the first transmission cavity;

(d) receiving the tray loaded with the silicon wafer from the first CVD process chamber by the first transmission chamber, and correspondingly conveying the tray to a first unloading chamber of the first CVD equipment;

(e) receiving the tray which comes from the first conveying cavity and bears the silicon wafers by the first unloading cavity, and conveying the tray to a first blanking position of the first CVD equipment so as to blank the silicon wafers from the tray;

(f) receiving a blanked silicon wafer from a first blanking position of the first CVD equipment by a silicon wafer overturning device, overturning the silicon wafer to enable the first surface of the silicon wafer to be exchanged with a second surface opposite to the first surface, and conveying the overturned silicon wafer to a second loading position of the second CVD equipment for loading to a tray;

(g) receiving, by a second load chamber of the second CVD apparatus, the tray from the second loading position and carrying the flipped silicon wafer;

(h) receiving the tray loaded with the silicon wafer from the second loading cavity by a second transmission cavity of the second CVD equipment, and correspondingly conveying the tray to any available second CVD process cavity in a plurality of second CVD process cavities;

(i) depositing a second amorphous silicon film different from the first amorphous silicon film on the second surface of the silicon wafer in sequence by the second CVD process chamber through a second intrinsic CVD process and a P-type or N-type doping CVD process, and correspondingly conveying the tray carrying the silicon wafer of which the second surface is deposited to the second transmission chamber;

(j) receiving the tray loaded with the silicon wafer from the second CVD process chamber by the second transmission chamber, and conveying the tray to a second unloading chamber of the second CVD equipment; and

(k) receiving the tray which comes from the second transmission cavity and bears the silicon wafers by the second unloading cavity, and conveying the tray to a blanking position so as to blank the silicon wafers from the tray.

9. The plating method according to claim 8, wherein the step (c) comprises the steps of:

(c1) heating the silicon wafer to a preset film forming temperature by the first CVD process chamber;

(c2) providing a gas required for performing the first intrinsic CVD process from the first CVD process chamber and decomposing it using PECVD plasma or thermally dissociating it using HWCVD, thereby depositing a type I amorphous silicon thin film on the first side of the silicon wafer; and

(c3) providing a gas required for performing the N-type or P-type doping CVD process from the first CVD process chamber and decomposing it using PECVD plasma or thermally dissociating it using HWCVD, thereby depositing the first amorphous silicon thin film selected from the N-type and P-type amorphous silicon thin films on the first face;

wherein the preset film-forming temperature of the silicon wafer is within the range of 100-300 ℃, the gas required for performing the first intrinsic CVD process in the step (c2) comprises silane or silane and hydrogen, the gas required for performing the N-type doped CVD process in the step (c3) comprises silane or silane and hydrogen, and further comprises phosphane, and the gas required for performing the P-type doped CVD process comprises silane or silane and hydrogen, and further comprises diborane or trimethylboron.

10. The plating method according to claim 8, wherein the step (i) comprises the steps of:

(i1) heating the silicon wafer to the preset film forming temperature by the second CVD process chamber;

(i2) providing a gas required for performing the second intrinsic CVD process from the second CVD process chamber and decomposing it using PECVD plasma or thermally dissociating it using HWCVD, thereby depositing a type I amorphous silicon thin film on the second side of the silicon wafer; and

(i3) providing a gas required for performing the P-type or N-type doping CVD process from the second CVD process chamber and decomposing it using PECVD plasma or thermally dissociating it using HWCVD, thereby depositing the second amorphous silicon thin film selected from the N-type and P-type amorphous silicon thin films on the second face;

wherein the preset film-forming temperature of the silicon wafer is within the range of 100-300 ℃, the gas required for performing the second intrinsic CVD process in the step (i2) comprises silane or silane and hydrogen, the gas required for performing the N-type doped CVD process in the step (i3) comprises silane or silane and hydrogen, and further comprises phosphane, and the gas required for performing the P-type doped CVD process comprises silane or silane and hydrogen, and further comprises diborane or trimethylboron.