PVD Equipment and PVD Deposition Method

Abstract

The present invention provides a PVD device and a PVD deposition method. The PVD device includes a plurality of magnetron sputtering rotating cathodes arranged in a sputtering chamber. The magnetron sputtering rotating cathodes include a first rotating cathode near the entrance of the sputtering chamber and a plurality of second rotating cathodes located between the first rotating cathode and the exit of the sputtering chamber. The diameter of the first rotating cathode is 50%-80% of the diameter of the second rotating cathode. The operating power of the first rotating cathode is 50%-60% of the operating power of the second rotating cathode. The first rotating cathode and the second rotating cathodes have the same target changing period. The present invention can inhibit the reduction of the efficiency of solar cells in the initial stage of target changing, improve the film forming uniformity and the target material utilization rate, and improve the running time and the target changing period of the PVD device.

Description

Technical Field

[0001] The present invention relates to the field of solar cell manufacturing, and particularly to PVD equipment and a PVD deposition method. Background Art

[0002] Silicon-based thin film heterojunction cells (HIT or HJT) are the third generation of high-efficiency solar cell technologies. They combine the advantages of the first-generation crystalline silicon and the second-generation silicon thin films, have characteristics such as high conversion efficiency and low temperature coefficient, and have good market prospects. The first intrinsic passivation layer, N-type amorphous or microcrystalline layer on the front side of the silicon wafer of the HIT solar cell, and the second intrinsic amorphous or microcrystalline silicon passivation layer, P-type amorphous or microcrystalline layer on the back side of the silicon wafer are deposited by PECVD (Plasma Enhanced Chemical Vapor Deposition) process.

[0003] The first electrode and the second electrode formed on the N-type amorphous or microcrystalline layer and the P-type amorphous or microcrystalline layer are deposited by Physical Vapor Deposition (PVD) process. The magnetron sputtering process is one of the most commonly used PVD processes on the market. The working principle of magnetron sputtering is that electrons collide with argon atoms during the flight to the substrate (such as a silicon wafer) under the action of the electric field E, causing it to ionize to produce Ar positive ions and new electrons; the new electrons fly to the substrate, and the Ar positive ions are accelerated towards the cathode target under the action of the electric field and bombard the target surface with high energy, causing the target material to sputter.

[0004] As Figure 1 shown, the magnetron sputtering PVD equipment in the prior art includes a plurality of magnetron sputtering rotary cathodes 10, 11, 12 arranged in the sputtering chamber 1. Each rotary cathode 10, 11, 12 has the same diameter and uses the same power for sputtering, and the target replacement cycle of each target material is basically the same. The substrate 2 is conveyed through the sputtering chamber 1 from left to right by the roller group 13 in the arrow direction, so as to deposit the TCO thin film at three target positions in sequence.

[0005] In the initial stage of target replacement of the magnetron sputtering cathode target (about 20%-25% of the entire target material service life), the target material has not been consumed yet, the distance between the target surface and the magnet cathode is relatively far, and the magnetic field strength is also relatively low. In order to improve the production capacity of the PVD equipment and reduce the efficiency fluctuation in the initial stage of target replacement, the power used by the magnetron sputtering cathode is relatively high (for example, about 8.7 KW), and the target voltage is also relatively high (for example, about 300 V). During the film formation process, oxygen negative ions in the plasma will bombard the amorphous or microcrystalline layer deposited by PECVD under the action of the cathode, causing damage. The higher the voltage, the greater the damage to the PECVD amorphous or microcrystalline layer, resulting in battery efficiency loss.

[0006] The current further improvement measure is to increase the magnetic field strength. After the magnetic field strength is increased, the collision probability of the plasma can be increased, the current rises, and the voltage drops. However, there are also the following problems with the current method of increasing the magnetic field strength: the strong magnetic field will cause problems with film formation uniformity; poor uniformity will further lead to too fast local consumption of the target, resulting in a shortened target replacement cycle, low target utilization rate, and low equipment operation rate.

[0007] Therefore, how to provide a PVD device and a PVD deposition method to solve the reduction of the efficiency of solar cells in the initial stage of target replacement, improve the film formation uniformity and target utilization rate, and increase the operation time (uptime) and target replacement cycle of the equipment has become a technical problem urgently to be solved in the industry. Summary of the Invention

[0008] In view of the above problems of the prior art, the present invention proposes a PVD device, which includes a plurality of magnetron sputtering rotating cathodes arranged in a sputtering chamber. The magnetron sputtering rotating cathode includes a first rotating cathode near the sputtering chamber entrance and a plurality of second rotating cathodes located between the first rotating cathode and the sputtering chamber exit. The diameter of the first rotating cathode is 50%-80% of the diameter of the second rotating cathode, the working power of the first rotating cathode is 50%-60% of the working power of the second rotating cathode, and the first rotating cathode and the second rotating cathode have the same target replacement cycle.

[0009] In one embodiment, the working power of the first rotating cathode is 45%-50% of the rated power of the rotating cathode, the working power of the second rotating cathode is 85% of the rated power of the rotating cathode, and the rated power range of the rotating cathode is 8KW-9KW.

[0010] In one embodiment, the working voltage range of the first rotating cathode is 250V-270V, the working voltage range of the second rotating cathode is 290V-310V, the magnetic field strength range of the first rotating cathode is 750G-800G, and the magnetic field strength range of the second rotating cathode is 800G-900G.

[0011] In one embodiment, the diameter range of the second rotating cathode is 100mm-200mm, the diameter range of the first rotating cathode is 50mm-160mm, and the target thickness range on the first rotating cathode and the second rotating cathode is 5mm-15mm.

[0012] In one embodiment, the PVD device further includes a third rotating cathode disposed between the first rotating cathode and the plurality of second rotating cathodes. The diameter, working power, and working voltage of the third rotating cathode are correspondingly the same as those of the first rotating cathode.

[0013] The present invention also provides a PVD deposition method, which includes the following steps:

[0014] (a). Evacuate the sputtering chamber of the PVD equipment and transfer the carrier plate carrying the silicon wafer into it;

[0015] (b). Deposit a TCO film on the silicon wafer through a first rotating cathode disposed near the sputtering chamber entrance in the sputtering chamber;

[0016] (c). Continuously deposit a TCO film on the silicon wafer through a plurality of second rotating cathodes in the sputtering chamber;

[0017] (d). Transfer the carrier plate carrying the silicon wafer out of the sputtering chamber;

[0018] Wherein the diameter of the first rotating cathode is 50%-80% of the diameter of the second rotating cathode, the working power of the first rotating cathode is 50%-60% of the working power of the second rotating cathode, and the first rotating cathode and the second rotating cathode have the same target changing period.

[0019] In one embodiment, the working power of the first rotating cathode is 45%-50% of the rated power of the rotating cathode, the working power of the second rotating cathode is 85% of the rated power of the rotating cathode, and the rated power range of the rotating cathode is 8KW-9KW.

[0020] In one embodiment, the working voltage range of the first rotating cathode is 250V-270V, the working voltage range of the second rotating cathode is 290V-310V, the magnetic field intensity range of the first rotating cathode is 750G-800G, and the magnetic field intensity range of the second rotating cathode is 800G-900G.

[0021] In one embodiment, the diameter range of the second rotating cathode is 100mm-200mm, the diameter range of the first rotating cathode is 50mm-160mm, and the target thickness range on the first rotating cathode and the second rotating cathode is 5mm-15mm.

[0022] In one embodiment, the PVD deposition method further includes the following step between steps (b) and (c): (b0) Continuously deposit a TCO film on the silicon wafer through a third rotating cathode disposed in the sputtering chamber and between the first rotating cathode and the plurality of second rotating cathodes; the diameter, working power, and working voltage of the third rotating cathode correspond to those of the first rotating cathode.

[0023] Compared with the sputtering chamber in the prior art where the rotating cathode has the same diameter and working power, the PVD device of the present invention includes a plurality of magnetron sputtering rotating cathodes arranged in the sputtering chamber. The magnetron sputtering rotating cathode includes a first rotating cathode near the sputtering chamber inlet and a plurality of second rotating cathodes located between the first rotating cathode and the sputtering chamber outlet. The diameter of the first rotating cathode is 50%-80% of the diameter of the second rotating cathode, and the working power of the first rotating cathode is 50%-60% of the working power of the second rotating cathode. The first rotating cathode and the second rotating cathode have the same target-changing cycle. The present invention can inhibit the reduction of the solar cell efficiency at the initial stage of target changing, improve the film-forming uniformity and the target utilization rate, and improve the running time and target-changing cycle of the PVD device. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] After reading the detailed description of the embodiments of the present disclosure in conjunction with the following drawings, the above features and advantages of the present invention can be better understood. In the drawings, the components are not necessarily drawn to scale, and components with similar relevant characteristics or features may have the same or similar reference numerals.

[0025] Figure 1 It is a schematic structural diagram of the PVD device in the prior art.

[0026] Figure 2 It is a schematic structural diagram of an embodiment of the PVD device of the present invention.

[0027] Figure 3 It is a schematic structural diagram of another embodiment of the PVD device of the present invention.

[0028] Figure 4 It is a schematic flowchart of an embodiment of the PVD deposition method of the present invention.

[0029] Figure 5 It is a schematic flowchart of another embodiment of the PVD deposition method of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0030] The present invention will be described in detail below with reference to the drawings and specific embodiments to better understand the purpose, features and advantages of the present invention. It should be understood that the aspects described below in conjunction with the drawings and specific embodiments are merely exemplary and should not be construed as imposing any limitation on the protection scope of the present invention. Unless otherwise explicitly specified in the context, the singular forms "a" and "the" include plural referents. The terms "first", "second" and similar terms used in this specification and the claims do not denote any order, quantity or importance, but are only used to distinguish different components.

[0031] See Figure 2, which is a schematic structural diagram of an embodiment of the PVD device of the present invention. As Figure 2 shown, the PVD device of the present invention includes a plurality of magnetron sputtering rotary cathodes arranged in the sputtering chamber 3. The magnetron sputtering rotary cathode includes a first rotary cathode 30 near the sputtering chamber inlet E1 and a plurality of second rotary cathodes 31, 32, 33 located between the first rotary cathode 30 and the sputtering chamber outlet E2. The diameter of the first rotary cathode 30 is 50%-80% of the diameters of the second rotary cathodes 31, 32, 33, and the working power of the first rotary cathode 30 is 50%-60% of the working powers of the second rotary cathodes 31, 32, 33. The first rotary cathode 30 and the second rotary cathodes 31, 32, 33 have the same target changing period.

[0032] In Figure 2 the embodiment of the PVD device of the present invention shown, the magnetron sputtering rotary cathode includes three second rotary cathodes 31, 32, 33. The carrier plate 2 carrying the silicon wafers is fed into and out of the sputtering chamber 3 by the roller group 34.

[0033] The working power of the first rotary cathode 30 is 45%-50% of the rated power of the rotary cathode, and the working powers of the second rotary cathodes 31, 32, 33 are 85% of the rated power of the rotary cathode. The rated power range of the rotary cathode is 8KW-9KW, and the rated power of the rotary cathode can be more specifically 8.7KW.

[0034] The working voltage range of the first rotary cathode 30 is 250V-270V, the working voltage range of the second rotary cathodes 31, 32, 33 is 290V-310V, the magnetic field intensity range of the first rotary cathode 30 is 750G-800G, and the magnetic field intensity range of the second rotary cathodes 31, 32, 33 is 800G-900G.

[0035] The diameter range of the second rotary cathodes 31, 32, 33 is 100mm-200mm, the diameter range of the first rotary cathode 30 is 50mm-160mm, and the target thickness ranges on the first rotary cathode 30 and the second rotary cathodes 31, 32, 33 are both 5mm-15mm.

[0036] Figure 3 is a schematic structural diagram of another embodiment of the PVD device of the present invention. Figure 3 The embodiment shown is different from the Figure 2 embodiment shown in that Figure 3In the sputtering chamber 3" of the PVD device shown, in addition to the first rotating cathode 30, multiple second rotating cathodes 31, 32, 33 being provided, a third rotating cathode 35 is also provided between the first rotating cathode 30 and the multiple second rotating cathodes 31, 32, 33. The diameter, working power, and working voltage of the third rotating cathode 35 are correspondingly the same as those of the first rotating cathode 30.

[0037] See Figure 4 , in combination with Figure 2 , Figure 4 shows a schematic flow diagram of an embodiment of the PVD deposition method 40 of the present invention. As Figure 4 shown, the PVD deposition method 40 first performs step S410 of evacuating the sputtering chamber 3 of the PVD device and transferring the carrier plate 2 carrying the silicon wafer into the sputtering chamber 3. In this embodiment, the carrier plate 2 carrying the silicon wafer is transferred into the sputtering chamber 3 by the roller group 34.

[0038] The PVD deposition method 40 then proceeds to step S420 of depositing a TCO film on the silicon wafer through the first rotating cathode 30 disposed near the sputtering chamber inlet E1 in the sputtering chamber 3. In this embodiment, the working power of the first rotating cathode 30 is 45%-50% of the rated power of the rotating cathode, the rated power range of the rotating cathode is 8KW-9KW, and the rated power of the rotating cathode can be more specifically 8.7KW. The working voltage range of the first rotating cathode 30 is 250V-270V, and the magnetic field intensity range of the first rotating cathode 30 is 750G-800G. The diameter range of the first rotating cathode 30 is 50mm-160mm, and the target thickness range on the first rotating cathode 30 is 5mm-15mm.

[0039] The PVD deposition method 40 then proceeds to step S430 of continuing to deposit a TCO film on the silicon wafer through the multiple second rotating cathodes 31, 32, 33 in the sputtering chamber 3, wherein the diameter of the first rotating cathode 30 is 50%-80% of the diameters of the second rotating cathodes 31, 32, 33, the working power of the first rotating cathode 30 is 50%-60% of the working powers of the second rotating cathodes 31, 32, 33, and the first rotating cathode 30 and the second rotating cathodes 31, 32, 33 have the same target changing period. In this embodiment, the working power of the second rotating cathodes 31, 32, 33 is 85% of the rated power of the rotating cathode, and the rated power range of the rotating cathode is 8KW-9KW. The working voltage range of the second rotating cathodes 31, 32, 33 is 290V-310V, and the magnetic field intensity range of the second rotating cathodes 31, 32, 33 is 800G-900G. The diameter range of the second rotating cathodes 31, 32, 33 is 100mm-200mm, and the target thickness range on the second rotating cathodes 31, 32, 33 is 5mm-15mm.

[0040] The PVD deposition method 40 then proceeds to step S440 to transfer the carrier plate 2 carrying the silicon wafers out of the sputtering chamber 3. In this embodiment, the carrier plate 2 carrying the silicon wafers is transferred out of the sputtering chamber 3 by the roller group 34.

[0041] See Figure 5 , in combination with Figure 3 and Figure 4 , Figure 5 shows a schematic flow chart of another embodiment of the PVD deposition method of the present invention. Figure 5 The embodiment shown is different from Figure 4 the embodiment shown in that Figure 5 in the PVD deposition method 40” in addition to performing steps S410, S420, S430, S440, the PVD deposition method 40” also performs step S4200 between steps S420 and S430, and continues to deposit a TCO film on the silicon wafers through a third rotating cathode 35 disposed in the sputtering chamber 3 and between the first rotating cathode 30 and the plurality of second rotating cathodes 31, 32, 33; the diameter, working power, and working voltage of the third rotating cathode 35 correspond to the diameter, working power, and working voltage of the first rotating cathode 30.

[0042] The PVD device of the present invention includes a plurality of magnetron sputtering rotating cathodes arranged in a sputtering chamber. The magnetron sputtering rotating cathodes include a first rotating cathode near the sputtering chamber inlet and a plurality of second rotating cathodes located between the first rotating cathode and the sputtering chamber outlet. The diameter of the first rotating cathode is 50%-80% of the diameter of the second rotating cathode. The working power of the first rotating cathode is 50%-60% of the working power of the second rotating cathode. The first rotating cathode and the second rotating cathode have the same target changing period.

[0043] The present invention can suppress the reduction of the solar cell efficiency in the initial stage of target changing (about 20%-25% of the entire target material service life), can improve the film forming uniformity and the target material utilization rate, and can improve the operation time and target changing period of the PVD device. In the prior art, the solar cell efficiency in the initial stage of target changing is reduced by 0.2%-0.3% compared with the solar cell efficiency in other usage times of the target material. The present invention can improve the reduction of the solar cell efficiency in the initial stage of target changing compared with the solar cell efficiency in other usage times of the target material to no more than 0.1%.

[0044] The above embodiments are provided for those skilled in the art to implement or use the present invention. Those skilled in the art can make various modifications or changes to the above embodiments without departing from the inventive concept of the present invention. Therefore, the protection scope of the present invention is not limited by the above embodiments, but should be the maximum scope that conforms to the innovative features mentioned in the claims.

Claims

1. A PVD device, which includes a plurality of magnetron sputtering rotary cathodes arranged in a sputtering chamber, is characterized in that, The magnetron sputtering rotary cathode includes a first rotary cathode near the sputtering chamber inlet and a plurality of second rotary cathodes located between the first rotary cathode and the sputtering chamber outlet. The diameter of the first rotary cathode is 50%-80% of the diameter of the second rotary cathode. The working power of the first rotary cathode is 50%-60% of the working power of the second rotary cathode. The first rotary cathode and the second rotary cathode have the same target changing period; Wherein the working voltage range of the first rotary cathode is 250V-270V, the working voltage range of the second rotary cathode is 290V-310V, the magnetic field intensity range of the first rotary cathode is 750G-800G, and the magnetic field intensity range of the second rotary cathode is 800G-900G.

2. The PVD device according to claim 1, wherein The working power of the first rotary cathode is 45%-50% of the rated power of the rotary cathode, the working power of the second rotary cathode is 85% of the rated power of the rotary cathode, and the rated power range of the rotary cathode is 8KW-9KW.

3. The PVD device according to claim 1, characterized in that, The diameter range of the second rotary cathode is 100mm-200mm, the diameter range of the first rotary cathode is 50mm-160mm, and the target thickness ranges on the first rotary cathode and the second rotary cathode are both 5mm-15mm.

4. The PVD device according to claim 1, characterized in that, The PVD device further includes a third rotary cathode disposed between the first rotary cathode and the plurality of second rotary cathodes. The diameter, working power, and working voltage of the third rotary cathode are correspondingly the same as those of the first rotary cathode.

5. A PVD deposition method, characterized in that, It includes the following steps: (a). Evacuate the sputtering chamber of the PVD device and transfer the carrier plate carrying the silicon wafer into it; (b). Deposit a TCO film on the silicon wafer through the first rotary cathode disposed near the sputtering chamber inlet in the sputtering chamber; (c). Continuously deposit a TCO film on the silicon wafer through the plurality of second rotary cathodes in the sputtering chamber; and (d). Transfer the carrier plate carrying the silicon wafer out of the sputtering chamber; Wherein the diameter of the first rotary cathode is 50%-80% of the diameter of the second rotary cathode. The working power of the first rotary cathode is 50%-60% of the working power of the second rotary cathode. The first rotary cathode and the second rotary cathode have the same target changing period; The working voltage range of the first rotary cathode is 250V-270V, the working voltage range of the second rotary cathode is 290V-310V, the magnetic field intensity range of the first rotary cathode is 750G-800G, and the magnetic field intensity range of the second rotary cathode is 800G-900G.

6. The PVD deposition method according to claim 5, characterized in that, The working power of the first rotary cathode is 45%-50% of the rated power of the rotary cathode, the working power of the second rotary cathode is 85% of the rated power of the rotary cathode, and the rated power range of the rotary cathode is 8KW-9KW.

7. The PVD deposition method according to claim 5, characterized in that, The diameter range of the second rotating cathode is 100 mm - 200 mm, the diameter range of the first rotating cathode is 50 mm - 160 mm, and the thickness range of the target materials on the first rotating cathode and the second rotating cathode is 5 mm - 15 mm.

8. The PVD deposition method according to claim 5, wherein The PVD deposition method further includes the following step between steps (b) and (c): (b0) Continuously deposit a TCO film on the silicon wafer through a third rotating cathode disposed in the sputtering chamber and between the first rotating cathode and the plurality of second rotating cathodes; the diameter, working power, and working voltage of the third rotating cathode are correspondingly the same as those of the first rotating cathode.

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