Wafer boat cleaning equipment

Abstract

The utility model discloses wafer boat cleaning equipment, which comprises a cleaning cavity, a far-end plasma generator and a negative pressure extractor, wherein the cleaning cavity can be used for accommodating a wafer boat; the far-end plasma generator and the negative pressure extractor are communicated with the cleaning cavity; when the far-end plasma generator and the negative pressure extractor are started, plasma generated by the far-end plasma generator and used for cleaning is pumped into the cleaning cavity, a thin film deposited on the surface of the wafer boat in a furnace tube of another semiconductor processing device is removed in a dry mode, the cleaning time is effectively shortened to be within several hours, the carrying time and cost can be omitted, and the cleaning efficiency is improved. And the pickling safety accidents are reduced.

Description

Technical Field

[0001] The utility model relates to a crystal boat cleaning device, in particular to a crystal boat cleaning device for producing solar cells. Background Art

[0002] Solar cells are now widely used and have been mass-produced, and there are increasing expectations on how to improve manufacturing efficiency.

[0003] Solar cells are made using semiconductor processes, but because they are much larger than wafers, the size of semiconductor process equipment (such as PECVD equipment) is quite large. A wafer boat is prepared in the furnace tube of the semiconductor process equipment for solar cells, which is mainly used to fix the silicon substrates of multiple solar cells in it.

[0004] Because the wafer boat carries multiple silicon substrates and is about three meters long, after several coating processes, a thin film will be deposited on its surface, which must be cleaned and removed. The most common cleaning method is to pull the wafer boat out of the furnace tube of the semiconductor process equipment and move it to another place for chemical pickling. The pickling process is as follows: use a 15-25% hydrofluoric acid solution to clean it in three rounds, each for 4-5 hours; and perform periodic nitrogen bubbling during the soaking cleaning process, and rinse it for about half an hour; after pickling, rinse it with pure water for about 10 hours to confirm that the wafer boat has been cleaned, and then dry it (set at 100-120 degrees Celsius, run and maintain for 10-12 hours).

[0005] Therefore, to clean a wafer boat about three meters long, not including the transportation time, it takes more than one day of work to complete the cleaning. In addition, the hydrofluoric acid solution is volatile, and both the operators and the site require high-standard work safety planning, which is indeed not conducive to the production efficiency of solar cells and needs to be further improved. Utility Model Content

[0006] In view of the many shortcomings of the existing wafer boat cleaning technology for solar cell production, the main purpose of the utility model is to provide a new wafer boat cleaning device.

[0007] The main technical means used to achieve the above purpose is to make the wafer boat cleaning equipment include:

[0008] - Cleaning the cavity;

[0009] A remote plasma generator is connected to the cleaning chamber and provides a cleaning plasma to the cleaning chamber;

[0010] a negative pressure extractor connected to the cleaning chamber to create a negative pressure environment in the cleaning chamber; and

[0011] A wafer boat, for carrying a plurality of silicon substrates of solar cells, is arranged in the cleaning chamber.

[0012] The remote plasma generator comprises: a plasma generating chamber having a plasma outlet and at least one gas inlet, wherein the plasma outlet is connected to the cleaning chamber, and the gas inlet is used for inputting gas for ionization; and an impedance matcher for connecting a radio frequency power supply to input a radio frequency power supply into the plasma generating chamber.

[0013] The invention further comprises a nozzle, which is arranged in the cleaning cavity and corresponds to the plasma outlet of the remote plasma generator, and has a plurality of fine air channels.

[0014] The cleaning chamber is a metal cleaning chamber; the gas used by the remote plasma generator is a fluorine-containing gas; and the crystal boat is a graphite crystal boat, which includes two heating electrodes.

[0015] Wherein, the fluorine-containing gas is selected from NF 3 , CHF 3 CF 4 NF 3 , SF 6 , C 2 F 6 One or more mixed gases; and the negative pressure value of the negative pressure extractor in the cleaning chamber is 0.5 to 100 Torr.

[0016] The invention further comprises a heating power supply device which is electrically connected to the two heating electrodes of the graphite wafer boat so as to output power to the two heating electrodes to heat the graphite wafer boat.

[0017] The heating power supply device is a direct current power supply and heats the graphite crystal boat to a temperature between 150°C and 250°C.

[0018] The cleaning chamber has an inlet for the wafer boat to be placed on a top surface or one of its outer sides; the remote plasma generator is arranged on the top surface or one of the outer sides of the cleaning chamber; and the negative pressure extractor is arranged on a bottom surface or another relatively outer side of the cleaning chamber.

[0019] Among them, it further includes a rotating bracket, which includes: a plate body, on which a plurality of electrical insulating plates are laid, and a thermal expansion interval is maintained between adjacent electrical insulating plates, and two straight side plates are respectively arranged on two sides of the plate body; two electrical insulating fixing blocks are respectively fixed on the plate body and engaged with the two outer sides of the crystal boat; and two rotating shafts are respectively penetrated from two opposite outer sides of the cleaning chamber, and then passed through and fixed to the two straight side plates to rotate the plate body in the cleaning chamber.

[0020] Each of the electrical insulation fixing blocks is fixed on the board body after the fixing piece passes through the corresponding electrical insulation board longitudinally; and each of the electrical insulation fixing blocks is provided with a blocking piece corresponding to a front side of the wafer boat.

[0021] Each of the electrical insulating fixing blocks is L-shaped; the plate body and its two straight side plates are made of metal; and the electrical insulating plate and the electrical insulating fixing blocks are made of ceramic material.

[0022] The RF power supply is a 400kHz to 27.12MHz RF power supply, and the power is 1000W to 5000W.

[0023] From the above description, it can be seen that the wafer boat cleaning equipment of the present invention mainly arranges a remote plasma generator and a negative pressure extractor outside the cleaning chamber respectively. When the remote plasma generator and the negative pressure extractor are started, the cleaning plasma generated by the remote plasma generator is sucked into the cleaning chamber, and the thin film deposited on the surface of the wafer boat in the furnace tube of another semiconductor process equipment is dry-removed. The cleaning time is effectively shortened to within a few hours, and the transportation time and cost can be eliminated, reducing pickling work safety accidents.

[0024] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments, but is not intended to limit the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 : A cross-sectional schematic diagram of a first embodiment of the wafer boat cleaning device of the present invention.

[0026] Figure 2 : A cross-sectional schematic diagram of a second embodiment of the wafer boat cleaning device of the present invention.

[0027] Figure 3 : A partial three-dimensional schematic diagram of a third embodiment of the wafer boat cleaning device of the present invention.

[0028] Figure 4 : Figure 3 A partial side section view of .

[0029] Figure 5 : Figure 3 Another partial side sectional view of .

[0030] Wherein, the reference numerals are:

[0031] 10: Clean the cavity 11: Outside

[0032] 12: Outer side 13: Top side

[0033] 14: Entrance 15: Bottom

[0034] 20: Remote plasma generator 201: Plasma outlet

[0035] 202: Gas inlet 21: Plasma generation chamber

[0036] 22: Impedance matching device 23: RF power supply

[0037] 30: Negative pressure extractor 40: Crystal boat

[0038] 41: Heating electrode 42: Heating electrode

[0039] 50: Heating power supply device 501: Wire

[0040] 51: Nozzle 511: Fine airway

[0041] 60: Rotating bracket 61: Plate body

[0042] 611: Electrical insulation board 62: Straight side board

[0043] 621: Rotating shaft 622: Groove

[0044] 63: Electrically insulating fixing block 631: Fixing piece

[0045] 632:Block DETAILED DESCRIPTION

[0046] The utility model proposes a dry cleaning technology for a wafer boat used in the production of solar cells. The technical content is described in detail below with multiple embodiments and drawings.

[0047] First see Figure 1 FIG. 1 is a first embodiment of the wafer boat cleaning device of the present invention, which includes a cleaning chamber 10 , a remote plasma generator 20 , a negative pressure extractor 30 and a wafer boat 40 .

[0048] In this embodiment, the cleaning chamber 10 can be a metal cleaning chamber and can be made of aluminum or stainless steel. It is not a furnace tube for semiconductor coating. Therefore, the cleaning chamber of the utility model is not connected to semiconductor deposition process gas and other equipment. In this embodiment, the inlet 14 of the cleaning chamber 10 is opened on its top surface 13.

[0049] The above-mentioned remote plasma generator 20 (RPS) is connected to the cleaning chamber 10 to provide a cleaning plasma in the cleaning chamber 10. In this embodiment, the remote plasma generator 20 is fixed to one of the outer sides 11 of the cleaning chamber 10. The remote plasma generator 20 mainly includes a plasma generating chamber 21 and an impedance matcher 22. The plasma generating chamber 21 has a plasma outlet 201 and at least one gas inlet 202. The plasma outlet 201 is connected to the cleaning chamber 10, and the gas inlet 202 is used to input gas for removing thin films after ionization. In order to match the material of the above-mentioned metal cleaning chamber, the gas can be a fluorine-containing gas, which can be selected from one or more mixed gases of NF3, CHF3, CF4, NF3, SF6, C2F6, so that after the ionized gas is passed into the metal cleaning chamber, it will not etch the inner wall of the metal cleaning chamber. The impedance matcher 22 is connected to a radio frequency power supply 23, and the radio frequency power is input into the plasma generating chamber 21, and the gas in the plasma generating chamber 21 is dissociated to generate cleaning plasma, and then the plasma is sent into the cleaning chamber 10 through the plasma outlet 201. In one embodiment, the radio frequency power supply 23 is a radio frequency power supply 23 of 400kHz to 27.12MHz, and the power can be 1000W to 5000W. The higher the frequency, the higher the plasma density and ion concentration can be, and the lower the energy consumption can be, but the present invention is not limited thereto.

[0050] The negative pressure extractor 30 is connected to the cleaning chamber 10, so that the cleaning chamber 10 is in a negative pressure environment of about 0.5 to 100 Torr. In this embodiment, the negative pressure extractor 30 is fixed to the other relatively outer side 12 of the cleaning chamber 10; thus, when the negative pressure extractor 30 is activated, a negative pressure extraction airflow is generated in the cleaning chamber 10, and the cleaning plasma of the remote plasma generator 20 located at the relatively outer side 11 is evenly brought into the cleaning chamber 10, and the film particles generated after removal are taken away.

[0051] The wafer boat 40 is used to carry a plurality of silicon substrates of solar cells. The size of the wafer boat 40 matches the inlet 14 of the cleaning chamber 10, so it can be placed in the cleaning chamber 10 to clean the surface film. In this embodiment, the wafer boat 40 is placed in the cleaning chamber 10 from the inlet 14 located on the top surface 13 of the cleaning chamber 10. For solar cell manufacturers, the factory area does not need to be greatly expanded to place the dry cleaning equipment of the utility model, and the wafer boat 40 can be operated in and out of the cleaning chamber 10 with the help of the lifting mechanism.

[0052] In this embodiment, the wafer boat 40 can be made of graphite in combination with the gas selected by the above-mentioned remote plasma generator 20 to avoid etching of the wafer boat body such as quartz by the ionized gas. In addition, the graphite wafer boat can further include two heating electrodes 41 and 42. In order to improve the removal efficiency of the cleaning plasma acting on the thin film on the surface of the graphite wafer boat, the utility model can further include a heating power supply device 50, which is electrically connected to the two heating electrodes 41 and 42 of the wafer boat 40. Since graphite has conductive properties and its resistivity is about (8 to 13)×10 -6 Ω.m, so when graphite is directly electrified, it can convert electrical energy into thermal energy, so graphite is also a heating material. In this embodiment, the heating power supply device 50 is disposed outside the cleaning chamber 10 and can be a DC power supply. In one embodiment, the heating power supply device 50 can heat the wafer boat 40 to a temperature between about 150°C and 250°C. In one embodiment, two outer sides of the graphite wafer boat respectively extend outwardly with two heating electrodes 41 and 42.

[0053] The cleaning chamber 10 that can accommodate a wafer boat 40 of about three meters in length basically adopts the following four dry cleaning steps:

[0054]

[0055] As can be seen from the above table, the utility model performs dry cleaning operation, and the power output to the remote plasma generator 20 and the evacuation negative pressure value of the negative pressure extractor 30 increase with time to accelerate the cleaning efficiency of the thin film.

[0056] Furthermore, in order to make the cleaning plasma more evenly dispersed in the cleaning chamber 10, a nozzle 51 is provided at the plasma outlet 201 of the plasma generating chamber 21 in the cleaning chamber 10. The nozzle 51 has a plurality of fine air channels 511, so that the cleaning plasma enters the cleaning chamber 10 and passes through the fine air channels 511 to evenly enter the cleaning chamber 10.

[0057] Please see again Figure 2 FIG. 2 is a second embodiment of the wafer boat cleaning device of the present invention, most of the structures of which are the same as those of the first embodiment, except that the inlet 14 of the cleaning chamber 10 is opened on one of the outer sides 11 for the wafer boat 40 to enter and exit the cleaning chamber 10 laterally, and the remote plasma generator 20 is arranged on the top surface 13 of the cleaning chamber 10, the negative pressure extractor 30 is arranged on the bottom surface 15 of the cleaning chamber 10, and the nozzle 51 is arranged on the inner top surface of the cleaning chamber 10, so that when the cleaning plasma of the remote plasma generator 20 located above enters, it can be evenly distributed downward in the cleaning chamber 10 through the nozzle 51.

[0058] Please see again Figure 3As shown, it is a third embodiment of the wafer boat cleaning device of the utility model, and most of its structures are the same as the first and second embodiments, but it further includes a rotating bracket 60, and the rotating bracket 60 includes a plate body 61, two electrically insulating fixed blocks 63 and two rotating shafts 621; wherein a plurality of electrically insulating plates 611 are laid on the plate body 61, and a thermal expansion interval is maintained between adjacent electrically insulating plates 611, and two straight side plates 62 are respectively arranged on the two sides of the plate body 61, and the two straight side plates 62 are respectively provided for the two rotating shafts 621 to pass through, that is, the two rotating shafts 621 penetrate from the two opposite outer sides 11 and 12 of the cleaning chamber 10, and then pass through and are fixed to the two straight side plates 62. Please refer to Figure 4 As shown, the two electrically insulating fixed blocks 63 are respectively fixed on the plate body 61 after the fixing pieces 631 pass through each of the electrically insulating fixed blocks 63 and the corresponding electrically insulating plate 611 in the longitudinal direction, so as to engage with the two outer sides of the wafer boat 40; in one embodiment, each of the electrically insulating fixed blocks 63 is in an L shape, so as to engage between the two heating electrodes 41, 42 on the corresponding outer sides of the wafer boat 40; and the plate body 61 and its two straight side plates 62 are made of solid metal material, and the electrically insulating plate 611 and the electrically insulating fixed blocks 63 are made of ceramic material. Therefore, when the two rotating shafts 621 are rotated, the rotating bracket 60 and the wafer boat 40 thereon are driven to rotate, so that they are in more uniform contact with the cleaning plasma, thereby improving the cleaning efficiency.

[0059] Please refer to Figure 5 As shown, in order to make the wafer boat 40 more stable during rotation, each of the electrically insulating fixing blocks 63 corresponds to the front side of the wafer boat 40, that is, the front side of the heating electrode 42 located below, and a blocking piece 632 can be added to block the displacement of the wafer boat 40 during movement.

[0060] In order to cooperate with the embodiment of heating the graphite wafer boat, the two outer sides of the graphite wafer boat are fixed to the rotating bracket 60 by the two electrically insulating fixing blocks 63, and are electrically isolated from the plate body 61 by the electrically insulating plate 611 and the two electrically insulating fixing blocks 63, and the two heating electrodes 41 and 42 are passed through the through slots 622 of the corresponding straight side plates 62 by the wires 501, and pass through one of the corresponding outer sides 11 of the cleaning chamber 10 to be electrically connected to the power supply heating device 50, as shown in FIG. Figure 4 shown.

[0061] In summary, the wafer boat cleaning equipment of the present invention mainly arranges a remote plasma generator and a negative pressure extractor outside the cleaning chamber respectively. When the remote plasma generator and the negative pressure extractor are started, the cleaning plasma generated by the remote plasma generator is sucked into the cleaning chamber, and the thin film deposited on the surface of the wafer boat in the furnace tube of another semiconductor process equipment is dry-removed. The cleaning time is effectively shortened to within a few hours, and the transportation time and cost can be eliminated, thereby reducing pickling work safety accidents.

[0062] The above description is only an embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as above by the embodiment, it is not used to limit the present invention. Any person with ordinary knowledge in the technical field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of the technical solution of the present invention.

[0063] Of course, the present invention may have many other embodiments. Without departing from the spirit and essence of the present invention, technicians familiar with the field may make various corresponding changes and deformations based on the present invention, but these corresponding changes and deformations should all fall within the scope of protection of the claims of the present invention.

Claims

1. A wafer boat cleaning device, characterized in that: include: - Cleaning the cavity; A remote plasma generator is connected to the cleaning chamber and provides a cleaning plasma to the cleaning chamber; A negative pressure extractor is connected to the cleaning chamber to create a negative pressure environment in the cleaning chamber; as well as A wafer boat, for carrying a plurality of silicon substrates of solar cells, is arranged in the cleaning chamber.

2. The wafer boat cleaning device according to claim 1, characterized in that: The remote plasma generator comprises: a plasma generating chamber having a plasma outlet and at least one gas inlet, wherein the plasma outlet is connected to the cleaning chamber, and the gas inlet is used to input ionization gas; and An impedance matcher is connected to a radio frequency power supply to input a radio frequency power into the plasma generating chamber.

3. The wafer boat cleaning device according to claim 2, characterized in that: The invention further comprises a nozzle, which is arranged in the cleaning cavity and corresponds to the plasma outlet of the remote plasma generator, and has a plurality of fine air channels.

4. The wafer boat cleaning device according to claim 3, characterized in that: The cleaning chamber is a metal cleaning chamber; The gas used in the remote plasma generator is a fluorine-containing gas; and The wafer boat is a graphite wafer boat, and the graphite wafer boat includes two heating electrodes.

5. The wafer boat cleaning device according to claim 4, characterized in that: The fluorine-containing gas is selected from one of NF3, CHF3, CF4, NF3, SF6, and C2F6; and The negative pressure value extracted by the negative pressure extractor in the cleaning chamber is 0.5 to 100 Torr.

6. The wafer boat cleaning device according to claim 5, characterized in that: The invention further comprises a heating power supply device which is electrically connected to the two heating electrodes of the graphite wafer boat so as to output power to the two heating electrodes to heat the graphite wafer boat.

7. The wafer boat cleaning device according to claim 6, characterized in that: The heating power supply device is a direct current power supply and heats the graphite crystal boat to a temperature between 150°C and 250°C.

8. The wafer boat cleaning device according to any one of claims 1 to 7, characterized in that: The cleaning chamber has an inlet for the wafer boat to be placed in, which is opened on a top surface or one of the outer sides thereof; The remote plasma generator is disposed on the top surface or one of the outer sides of the cleaning chamber; and The negative pressure extractor is arranged on a bottom surface or another relatively outer side of the cleaning chamber.

9. The wafer boat cleaning device according to any one of claims 1 to 3, characterized in that: Further comprising a rotating bracket, comprising: A plate body, on which a plurality of electrical insulation plates are laid, and a thermal expansion interval is maintained between adjacent electrical insulation plates, and two straight side plates are respectively arranged on two sides of the plate body; Two electrically insulating fixing blocks are respectively fixed on the plate body and engaged with two outer sides of the wafer boat; and The two rotating shafts respectively penetrate from two opposite outer sides of the cleaning cavity, and then pass through and are fixed to the two straight side plates so as to rotate the plate body in the cleaning cavity.

10. The wafer boat cleaning device according to claim 9, characterized in that: Each of the electrical insulating fixing blocks is fixed to the plate body after the fixing piece passes longitudinally through the fixing piece and the corresponding electrical insulating plate; and Each of the electrical insulation fixing blocks is added with a blocking piece, and the blocking piece corresponds to a front side of the wafer boat.

11. The wafer boat cleaning device according to claim 9, characterized in that: Each of the electrical insulating fixing blocks is in an L shape; The board body and its two straight side panels are made of metal; and The electrical insulation plate and the electrical insulation fixing block are made of ceramic material.

12. The wafer boat cleaning device according to claim 2, characterized in that: The radio frequency power supply is a 400kHz to 27.12MHz radio frequency power supply, and the power is 1000W to 5000W.

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