A plasma generating method and a plasma processing method

Abstract

This invention provides a plasma generation method and a plasma processing method. The plasma generation method includes: using a plasma power supply to output pulse signals to a plasma generation component inside a processing cavity to generate plasma within the processing cavity; wherein the pulse width of the pulse signal is 0.5 ms–1 ms, and the pulse interval is 4 ms–7 ms. The processing method includes: performing plasma processing on the plasma obtained by the plasma generation method within the processing cavity. This plasma generation method can effectively improve the processing rate.

Description

Technical Field

[0001] This invention relates to the field of semiconductor technology, and more specifically to a plasma generation and processing method. Background Technology

[0002] In semiconductor manufacturing processes, deposition is an important process in semiconductor fabrication. Some deposition processes use plasma, such as plasma chemical vapor deposition (PCVD), plasma enhanced chemical vapor deposition (PECVD), and plasma enhanced atomic layer deposition (PEALD).

[0003] In photovoltaic production lines, tubular plasma-enhanced chemical vapor deposition (PCVD) technology is widely used to prepare silicon nitride (SiNx) thin films as front anti-reflective coatings and back protective films for PERC (Passivated Emitter and Rear Cell) and TOPCON (Tunnel Oxide Passivated Contact) cells. Generally, the plasma power supply in tubular PCVD equipment uses a 40kHz frequency and is coupled with a pulsed power supply output, where the on-time is 5-10ms and the off-time is 40-70ms. Compared to continuous output power supplies, pulsed output power supplies can effectively improve the intra-wafer uniformity of film thickness.

[0004] Currently, the suitable coating rate (i.e., coating efficiency) for high photoelectric conversion efficiency batteries is 5nm / min–8nm / min, which results in a coating time of 10–15 minutes per batch. Including preheating, vacuum breaking, loading, and unloading times, the total time for each process cycle is 30–45 minutes. To further reduce manufacturing costs and equipment investment costs, increasing the coating rate is one of the most effective methods. Shortening the coating process time for each batch not only increases the capacity of a single piece of equipment but also reduces the material consumption and energy consumption per unit of product.

[0005] In addition to its application in deposition processes, plasma is also used in other plasma treatments, such as plasma surface treatment processes.

[0006] However, the processing speed of existing plasma-based methods needs to be improved. Summary of the Invention

[0007] In view of this, the present invention provides a plasma generation method and a plasma processing method to solve the problem that the rate of plasma processing in the prior art needs to be improved.

[0008] The present invention provides a plasma generation method, comprising: using a plasma power supply to output a pulse signal to a plasma generation component inside a processing cavity to generate plasma in the processing cavity; wherein the pulse width corresponding to the pulse signal is 0.5ms-1ms and the pulse interval is 4ms-7ms.

[0009] Optionally, the pulse width is 0.55ms-0.8ms, and the pulse interval is 4.5ms-6.5ms.

[0010] Optionally, the pulse width is 0.6 ms and the pulse interval is 6 ms.

[0011] Optionally, the frequency of the pulse signal is 125Hz to 250Hz.

[0012] Optionally, the power corresponding to the pulse signal is 8KW to 18KW.

[0013] Optionally, it further includes: introducing a process gas into the processing chamber, wherein the plasma is formed by the process gas under the action of the pulse signal.

[0014] Optionally, the process gas includes a reactant gas and a protective gas.

[0015] Optionally, the protective gas includes argon.

[0016] Optionally, while using a plasma power supply to output a pulse signal with a pulse width of 0.5ms-1ms and a pulse interval of 4ms-7ms to the plasma generating component inside the processing cavity, a pulse signal with a pulse width of 5ms-10ms and a pulse interval of 40ms-70ms is also output.

[0017] Optionally, the plasma generation method includes an initial stage, an intermediate stage, and a final stage performed sequentially. In the initial stage, the pulse signal used has a pulse width of 0.5ms-1ms and a pulse interval of 4ms-7ms. In the intermediate stage, the pulse signal used has a pulse width of 5ms-10ms and a pulse interval of 40ms-70ms. In the final stage, the pulse signal used has a pulse width of 0.5ms-1ms and a pulse interval of 4ms-7ms.

[0018] Optionally, it also includes: a first overlapping stage located between the initial stage and the intermediate stage, and a second overlapping stage located between the intermediate stage and the final stage; in the first overlapping stage, the plasma generating component outputs a pulse signal with a pulse width of 0.5ms-1ms and a pulse interval of 4ms-7ms, while simultaneously outputting a pulse signal with a pulse width of 5ms-10ms and a pulse interval of 40ms-70ms; in the second overlapping stage, the plasma generating component outputs a pulse signal with a pulse width of 0.5ms-1ms and a pulse interval of 4ms-7ms, while simultaneously outputting a pulse signal with a pulse width of 5ms-10ms and a pulse interval of 40ms-70ms.

[0019] The present invention also provides a processing method, comprising: performing plasma processing in the processing cavity using the plasma obtained by the present invention.

[0020] Optionally, the plasma treatment is a coating process, in which a process film is deposited using the obtained plasma within the processing chamber.

[0021] Optionally, the deposition rate of the process film is 7 nm / min to 15 nm / min.

[0022] Optionally, the coating process includes plasma-enhanced chemical vapor deposition or plasma-enhanced atomic layer deposition.

[0023] Optionally, the material of the process film includes silicon-based materials.

[0024] Optionally, the material of the process film is silicon nitride; the coating process is plasma-enhanced chemical vapor deposition; the parameters of the coating process also include: the reaction gases used include SiH4 and NH3, the flow rate of SiH4 is 760sccm~780sccm, the flow rate of NH3 is 5500sccm~6500sccm, the chamber pressure in the processing chamber is 200Pa~220Pa, the power of the pulse signal is 10KW~15KW, and the temperature is 460℃~520℃.

[0025] Optionally, the parameters of the coating process further include: using a protective gas, with a flow rate ratio of protective gas to reactive gas of 1:8 to 1:20.

[0026] Optionally, the material of the process film is amorphous silicon; the coating process is plasma-enhanced chemical vapor deposition; the parameters of the coating process also include: the reaction gases used include SiH4 and Ar, the flow rate of SiH4 is 1800 sccm to 2200 sccm, the flow rate of Ar is 9400 sccm to 9800 sccm, the chamber pressure in the processing chamber is 230 Pa to 250 Pa, the power of the pulse signal is 8 kW to 12 kW, and the temperature is 410 °C to 430 °C.

[0027] Optionally, the parameters of the coating process further include: using a protective gas, with a flow rate ratio of protective gas to reactive gas of 4:1 to 8:1.

[0028] Optionally, the process film is used as a passivation film on the back of a PERC battery; the coating method includes: sequentially forming a first sub-process film and a second sub-process film in the same processing chamber, wherein the material of the first sub-process film includes aluminum oxide and the material of the second sub-process film includes silicon nitride.

[0029] Optionally, the coating process is a plasma-enhanced atomic layer deposition process; the plasma-enhanced atomic layer deposition process includes several sub-cycle depositions; in each sub-cycle deposition, the plasma generating component outputs the pulse signal.

[0030] The technical solution provided by this invention has the following effects:

[0031] The plasma generation method provided by this invention uses a plasma power supply to output pulse signals to a plasma generation component inside a processing cavity, thereby generating plasma within the processing cavity. The pulse width of the pulse signal is 0.5 ms–1 ms, and the pulse interval is 4 ms–7 ms. Both the pulse width and pulse interval are set relatively small, an order of magnitude lower than conventional pulse widths and intervals. The pulse signal has a relatively high frequency; high-frequency pulse signals are more conducive to plasma excitation, resulting in increased plasma density and higher particle energy within the plasma, which is beneficial for plasma-based process technologies.

[0032] The processing method provided by this invention uses plasma generated by the plasma generation method of this invention to perform plasma processing in the processing cavity. Since the pulse width corresponding to the pulse signal is 0.5ms-1ms and the pulse interval is 4ms-7ms, both the pulse width and pulse interval are set relatively small, and are an order of magnitude lower than conventional pulse widths and pulse intervals. This increases the plasma density and the particle energy in the plasma, effectively improving the plasma processing rate.

[0033] Furthermore, the plasma treatment is a coating process, in which a process film is deposited using the obtained plasma within the processing chamber. This effectively increases the coating rate by more than 50%.

[0034] Furthermore, in the coating method, when the power corresponding to the pulse signal is 8KW to 18KW, the power of the pulse signal used is relatively large. Combined with the special pulse width and pulse interval settings in this invention, the coating rate can be further significantly improved.

[0035] Furthermore, in the coating method, a process gas is introduced into the processing chamber, the process gas including a reactive gas and a protective gas; the protective gas can improve the stability of the plasma in the processing chamber, achieve stable coating, and avoid reducing the thickness uniformity of the process film. Attached Figure Description

[0036] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0037] Figure 1 This is a schematic diagram of the pulse signal provided by the plasma power supply during the plasma generation process according to an embodiment of the present invention;

[0038] Figure 2 This is a schematic diagram of radio frequency signals during neutron cyclic deposition in a coating process according to an embodiment of the present invention;

[0039] Figure 3 This is a comparison graph of the coating rates of Experimental Example 1 and Comparative Example 1 in one embodiment of the present invention.

[0040] Figure 4 This is a comparison diagram of the uniformity of the in-film coating in Experimental Example 1 and Comparative Example 1 in one embodiment of the present invention.

[0041] Figure 5 This is a comparison diagram of the inter-film coating uniformity of Experimental Example 1 and Comparative Example 1 in one embodiment of the present invention;

[0042] Figure 6 This is a comparison diagram of the minority carrier lifetime of the solar cells of Experimental Example 1 and Comparative Example 1 in one embodiment of the present invention.

[0043] Figure 7 This is a comparison diagram of the open-circuit voltage of the battery cells in Experimental Example 1 and Comparative Example 1 in one embodiment of the present invention.

[0044] Figure 8This is a comparison graph of the coating rates of Experimental Example 2 and Comparative Example 2 in one embodiment of the present invention;

[0045] Figure 9 This is a comparison diagram of the in-film coating uniformity of Experimental Example 2 and Comparative Example 2 in one embodiment of the present invention;

[0046] Figure 10 This is a comparison diagram of the inter-film coating uniformity of Experimental Example 2 and Comparative Example 2 in one embodiment of the present invention;

[0047] Figure 11 This is a comparison diagram of the minority carrier lifetime of the solar cells in Experimental Example 2 and Comparative Example 2 in one embodiment of the present invention.

[0048] Figure 12 This is a comparison diagram of the open-circuit voltage of the battery cells in Experimental Example 2 and Comparative Example 2 in one embodiment of the present invention. Detailed Implementation

[0049] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0050] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0051] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can also refer to the internal connection of two components; and they can refer to a wireless connection or a wired connection. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0052] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0053] This embodiment provides a plasma generation method, including: using a plasma power supply to output a pulse signal to a plasma generation component inside a processing cavity to generate plasma in the processing cavity; wherein the pulse width corresponding to the pulse signal is 0.5ms-1ms, and the pulse interval is 4ms-7ms.

[0054] In the plasma generation method of this embodiment, since the pulse width and pulse interval are both set to be small, and are an order of magnitude lower than the conventional pulse width and pulse interval, the frequency of the pulse signal is relatively high. The high-frequency pulse signal is more conducive to the excitation of plasma, thereby increasing the plasma density and the particle energy in the plasma, which is helpful for plasma-based process manufacturing.

[0055] In one embodiment, the pulse width is 0.55ms–0.8ms, and the pulse interval is 4.5ms–6.5ms. Preferably, refer to... Figure 1 In one specific embodiment, the pulse width is 0.6 ms and the pulse interval is 6 ms.

[0056] In one embodiment, the frequency of the pulse signal is 125Hz to 250Hz. A higher frequency pulse signal is more beneficial for plasma excitation. Preferably, the frequency of the pulse signal is 180Hz.

[0057] In one embodiment, the power corresponding to the pulse signal is 8KW to 18KW, for example, 8KW, 10KW, 12KW, 14KW, 16KW, or 18KW. The high power of the pulse signal, combined with the special pulse width and pulse interval settings in this embodiment, significantly increases the particle energy in the plasma.

[0058] In this embodiment, the method further includes: introducing a process gas into the processing chamber, the process gas including a reactive gas and a protective gas, the protective gas including an inert protective gas, such as argon; the plasma is formed by the process gas under the action of the pulse signal. The protective gas can improve the stability of the plasma within the processing chamber.

[0059] In one embodiment, while using a plasma power supply to output a pulse signal with a pulse width of 0.5ms-1ms and a pulse interval of 4ms-7ms to the plasma generating component inside the processing cavity, a pulse signal with a pulse width of 5ms-10ms and a pulse interval of 40ms-70ms is also output.

[0060] In another embodiment, the plasma generation method includes an initial stage, an intermediate stage, and a final stage performed sequentially. In the initial stage, the pulse signal used has a pulse width of 0.5 ms to 1 ms and a pulse interval of 4 ms to 7 ms. In the intermediate stage, the pulse signal used has a pulse width of 5 ms to 10 ms and a pulse interval of 40 ms to 70 ms. In the final stage, the pulse signal used has a pulse width of 0.5 ms to 1 ms and a pulse interval of 4 ms to 7 ms. Furthermore, it also includes: a first overlapping stage located between the initial stage and the intermediate stage, and a second overlapping stage located between the intermediate stage and the final stage; in the first overlapping stage, the plasma generating component outputs a pulse signal with a pulse width of 0.5ms-1ms and a pulse interval of 4ms-7ms, while simultaneously outputting a pulse signal with a pulse width of 5ms-10ms and a pulse interval of 40ms-70ms; in the second overlapping stage, the plasma generating component outputs a pulse signal with a pulse width of 0.5ms-1ms and a pulse interval of 4ms-7ms, while simultaneously outputting a pulse signal with a pulse width of 5ms-10ms and a pulse interval of 40ms-70ms.

[0061] For plasma generating components that output pulse signals with a pulse width of 0.5ms-1ms and a pulse interval of 4ms-7ms, which enable rapid thin film growth, after the plasma has been applied for a period of time and stabilized, using conventional pulse signals with an output pulse width of 5ms-10ms and a pulse interval of 40ms-70ms can still maintain the corresponding technical effect. Relatively large pulse intervals can be used until the end of the process. However, at the end of the processing / process, using pulse signals with a pulse width of 0.5ms-1ms and a pulse interval of 4ms-7ms can further ensure the quality of the thin film.

[0062] When using the above specific method, two or more sets of plasma generating components and multiple sets of plasma power supplies can be installed in the processing chamber. When there are no multiple different types of pulses, one set of power supply and plasma generating components can be used. When there are multiple different types of pulses, different plasma generating units and corresponding plasma power supplies can be used, with one plasma generating unit and one corresponding plasma power supply generating one type of pulse signal.

[0063] The plasma generated in this embodiment can be used in plasma-related processing processes or methods such as film deposition and etching processes.

[0064] The plasma generation method generates plasma through inductive coupling or capacitive coupling. The equipment used in the plasma generation method is an inductively coupled plasma device or a capacitively coupled plasma device. The working principle of the inductively coupled plasma device includes: radio frequency power supplied by the plasma power source is fed into an inductor coil at the top of the processing cavity through a radio frequency matching unit. The radio frequency current in the inductor coil generates an alternating magnetic field perpendicular to the current plane inside the processing cavity. This alternating magnetic field induces an angular electric field parallel to the coil current direction inside the processing cavity. The process gas inside the processing cavity generates inductively coupled plasma under the influence of this angular electric field. The density distribution of the inductively coupled plasma can be controlled by the magnitude of the radio frequency power in the inductor coil.

[0065] Another embodiment of the present invention provides a processing method, comprising: performing plasma processing in the processing cavity on plasma obtained by the plasma generation method described above.

[0066] The processing method provided in this embodiment of the invention uses plasma generated by the plasma generation method described above to perform plasma processing within the processing cavity. Since the pulse width corresponding to the pulse signal is 0.5ms-1ms and the pulse interval is 4ms-7ms, both the pulse width and pulse interval are set relatively small, and are an order of magnitude lower than conventional pulse widths and intervals. This increases the plasma density and the particle energy in the plasma, effectively improving the plasma processing rate.

[0067] Because plasma processing is improved, production capacity is increased, reactant consumption and power consumption are reduced, and the production and investment costs of plasma processing are lowered.

[0068] Furthermore, the plasma treatment is a coating process, in which a process film is deposited using the obtained plasma within the treatment chamber. This effectively increases the coating rate, by more than 50%. Because of the increased coating rate, production capacity is improved, reactant consumption and energy consumption are reduced, and the production and investment costs of the coating method are lowered.

[0069] In one embodiment, the deposition rate of the process film is 7nm / min to 15nm / min, for example, 7nm / min, 8nm / min, 9nm / min, 10nm / min, 11nm / min, 12nm / min, 13nm / min, 14nm / min or 15nm / min.

[0070] The coating process includes plasma chemical vapor deposition, plasma-enhanced chemical vapor deposition, or plasma-enhanced atomic layer deposition.

[0071] In one specific embodiment, the plasma-enhanced chemical vapor deposition (PECVD) process includes a tubular PECVD process. The tubular PECVD process can be used to coat photovoltaic cells mounted on graphite boats.

[0072] The equipment used for the coating process includes inductively coupled plasma deposition equipment or capacitively coupled plasma deposition equipment.

[0073] In the coating method, when the power of the pulse signal is 8KW to 18KW, the power of the pulse signal used is relatively large. Combined with the special pulse width and pulse interval settings in this invention, the coating rate can be further improved significantly.

[0074] In the coating method, a process gas is introduced into the processing chamber. The process gas includes a reactive gas and a protective gas. The protective gas improves the stability of the plasma within the processing chamber, achieving stable coating and preventing a reduction in the uniformity of the coating thickness. The protective gas includes an inert protective gas.

[0075] In one embodiment, the material of the process film includes silicon-based materials, such as amorphous silicon or silicon nitride.

[0076] In one embodiment, the process film is made of silicon nitride. In another embodiment, the process film is made of amorphous silicon, further comprising hydrogenated amorphous silicon (a-Si:H). It should be noted that the material of the process film is not limited to the above-mentioned materials, and the deposition method can also be used to form process films of other materials.

[0077] When the plasma-enhanced chemical vapor deposition (PECVD) process is a tubular PECVD process, and the coating treatment is used to coat photovoltaic cells supported on a graphite boat, the coating treatment further includes: a boat loading step, a preheating step, a leak detection step, and a pre-deposition step performed sequentially before deposition; and a pipeline purging step, a cavity purging step, a processing chamber vacuum breaking step, and a boat unloading step performed sequentially after deposition. Specifically, the boat loading step refers to placing the cell inside the graphite boat and placing the graphite boat inside the processing chamber; the preheating step refers to preheating the processing chamber; the leak detection step refers to checking the airtightness of the processing chamber; in the pre-deposition step, the plasma power supply pulse signal is not applied to the processing chamber, and process gas is introduced into the processing chamber to adjust the pressure inside the processing chamber; the gas used in the pipeline purging step and the cavity purging step includes nitrogen. The processing chamber vacuum breaking step can use nitrogen to break the vacuum. The boat unloading step refers to removing the cell from the graphite boat. In one embodiment, the flow rate of the process gas in the deposition step is the same as that in the pre-deposition step, and the pressure in the processing chamber in the deposition step is the same as that in the processing chamber in the pre-deposition step.

[0078] The process film can have one or more layers. The materials of multilayer process films can be the same or different. Within each process film layer, pulse signals with output pulse widths of 0.5ms–1ms and pulse intervals of 4ms–7ms, and pulse signals with output pulse widths of 5ms–10ms and pulse intervals of 40ms–70ms can be continuously switched to form stacks deposited under different pulse signals. Furthermore, by coordinating with changes in gas composition, the properties can be further controlled, for example, in silicon nitride thin film deposition to adjust the refractive index of the silicon nitride thin film.

[0079] In one embodiment, the material of the process film is silicon nitride, and the coating process is plasma-enhanced chemical vapor deposition. The parameters of the coating process include: the reaction gases used are SiH4 and NH3, the flow rate of SiH4 is 760 sccm to 780 sccm, for example 770 sccm, the flow rate of NH3 is 5500 sccm to 6500 sccm, for example 6000 sccm, the chamber pressure in the processing chamber is 200 Pa to 220 Pa, for example 210 Pa, the power of the pulse signal is 10 kW to 15 kW, for example 12 kW, and the temperature is 460 °C to 520 °C; the pulse width corresponding to the pulse signal output by the plasma power supply to the processing chamber is 0.5 ms to 1 ms, for example 0.6 ms, and the pulse interval is 4 ms to 7 ms, for example 6 ms. Furthermore, based on this, the plasma-enhanced chemical vapor deposition (PECVD) process is a tubular PECVD process. The coating treatment is used to coat photovoltaic cells supported on a graphite boat. The number of photovoltaic cells supported by the graphite boat is 480. The substrate morphology used for the photovoltaic cells is an alkaline polished morphology, and the heating temperature of the substrate is 460℃-520℃. Further, the parameters of the coating treatment also include: using a protective gas, with a flow ratio of protective gas to reactive gas of 1:8-1:20. The protective gas accounts for a relatively small proportion of the process gas flow, thus improving the stability of the plasma within the processing chamber while minimizing its impact on the plasma density. The protective gas includes an inert protective gas.

[0080] In one embodiment, the material of the process film is amorphous silicon, and the coating process is plasma-enhanced chemical vapor deposition. The parameters of the coating process include: the reactive gases used are SiH4 and Ar, the flow rate of SiH4 is 1800 sccm–2200 sccm, the flow rate of Ar is 9400 sccm–9800 sccm, the chamber pressure in the processing chamber is 230 Pa–250 Pa, the power of the pulse signal is 8 kW–12 kW, the temperature is 410 °C–430 °C, and the pulse width corresponding to the pulse signal output by the plasma power supply to the processing chamber is 0.5 ms–1 ms, for example, 0.6 ms, and the pulse interval is 4 ms–7 ms, for example, 6 ms. Hydrogen gas can also be introduced in this coating method. Furthermore, based on this, the plasma-enhanced chemical vapor deposition (PECVD) process is a tubular PECVD process. The coating treatment is used to coat photovoltaic cells supported on a graphite boat. The number of photovoltaic cells supported by the graphite boat is 480. The substrate morphology used for the photovoltaic cells is an alkaline polished morphology, and the heating temperature of the substrate is 410℃–430℃. Further, the parameters of the coating method also include: using a protective gas, with a protective gas to reactant gas flow ratio of 4:1 to 8:1. The protective gas improves the stability of the plasma within the processing chamber. The protective gas includes an inert protective gas.

[0081] In one embodiment, the process film is used as a passivation film on the back side of a PERC cell; the coating method includes: sequentially forming a first sub-process film and a second sub-process film in the same processing chamber, wherein the material of the first sub-process film includes aluminum oxide, and the material of the second sub-process film includes silicon nitride. Because the first and second sub-process films are sequentially formed in the same processing chamber, there are fewer interface defects between the first and second sub-process films, thus improving the passivation effect of the passivation film on the back side of the PERC cell.

[0082] In one embodiment, reference Figure 2 The coating process is a plasma-enhanced atomic layer deposition (PEALD) process; the PALD process includes several sub-cycle depositions; each sub-cycle deposition is used to deposit one atomic layer film; in each sub-cycle deposition, the plasma generating component outputs the pulse signal. Further, in each sub-cycle deposition, a protective gas and an oxygen source are continuously introduced into the processing chamber, or, in each sub-cycle deposition, a protective gas and a nitrogen source are continuously introduced into the processing chamber. In each sub-cycle deposition, a silicon precursor flow is also introduced; after the silicon precursor flow is introduced, the plasma generating component outputs the pulse signal. The protective gas includes an inert protective gas.

[0083] Example 1: The material of the process film is silicon nitride, and the coating process is tubular plasma-enhanced chemical vapor deposition. The coating process is used to coat photovoltaic cells supported on a graphite boat. The parameters of the coating process include: the reaction gases used are SiH4 and NH3, the flow rate of SiH4 is 770 sccm, the flow rate of NH3 is 6000 sccm, the chamber pressure in the processing chamber is 210 Pa, the power of the pulse signal is 12 kW, the pulse width corresponding to the pulse signal output by the plasma power supply to the processing chamber is 0.6 ms, and the pulse interval is 6 ms; the number of photovoltaic cells supported on the graphite boat is 480, the substrate morphology used for the photovoltaic cells is alkaline polished morphology, the heating temperature of the substrate is 460℃-520℃, and the coating time is 10 min.

[0084] Comparative Example 1: The material of the process film is silicon nitride, and the coating process is tubular plasma-enhanced chemical vapor deposition. The coating process is used to coat photovoltaic cells supported on a graphite boat. The parameters of the coating process include: the reaction gases used are SiH4 and NH3, the flow rate of SiH4 is 770 sccm, the flow rate of NH3 is 6000 sccm, the chamber pressure in the processing chamber is 210 Pa, the power of the pulse signal is 12 kW, the pulse width corresponding to the pulse signal output by the plasma power supply to the processing chamber is 6 ms, and the pulse interval is 60 ms; the number of photovoltaic cells supported on the graphite boat is 480, the substrate morphology used for the photovoltaic cells is alkaline polished morphology, the heating temperature of the substrate is 460℃-520℃, and the coating time is 10 min.

[0085] Example 2: The material of the process film is amorphous silicon, and the coating process is tubular plasma-enhanced chemical vapor deposition. The coating process is used to coat photovoltaic cells supported on a graphite boat. The parameters of the coating process include: the reaction gases used are SiH4 and Ar, the flow rate of SiH4 is 2000 sccm, the flow rate of Ar is 9600 sccm, the chamber pressure in the processing chamber is 240 Pa, and the power of the pulse signal is 10 kW. The pulse width corresponding to the pulse signal output by the plasma power supply to the processing chamber is 0.6 ms, and the pulse interval is 6 ms. The number of photovoltaic cells supported on the graphite boat is 480, the substrate morphology used for the photovoltaic cells is alkaline polished, and the heating temperature of the substrate is 420℃.

[0086] Comparative Example 2: The material of the process film is amorphous silicon, and the coating process is tubular plasma-enhanced chemical vapor deposition. The coating process is used to coat photovoltaic cells supported on a graphite boat. The parameters of the coating process include: the reaction gases used are SiH4 and Ar, the flow rate of SiH4 is 2000 sccm, the flow rate of Ar is 9600 sccm, the chamber pressure in the processing chamber is 240 Pa, and the power of the pulse signal is 10 kW. The pulse width corresponding to the pulse signal output by the plasma power supply to the processing chamber is 6 ms, and the pulse interval is 60 ms. The number of photovoltaic cells supported on the graphite boat is 480, the substrate morphology used for the photovoltaic cells is alkaline polished, and the heating temperature of the substrate is 420 ℃.

[0087] The batteries obtained from Experimental Example 1 and Comparative Example 1 were tested, including a coating rate test (see reference). Figure 3 ), In-film coating uniformity test (reference) Figure 4 Inter-film coating uniformity test (reference) Figure 5 Spoon life test (reference) Figure 6 ) and open-circuit voltage test (reference) Figure 7 ). Figure 3 The unit of the vertical axis is nm / min. Figure 6 The unit of the vertical axis is us. Figure 7 The unit of the vertical axis is mV. Figure 3 The results show that the coating rate of Experimental Example 1 was 10 nm / min, while the coating rate of Comparative Example 1 was 6 nm / min. The coating rate of Experimental Example 1 was significantly improved compared to that of Comparative Example 1. Figure 4 The results show that the on-wafer coating uniformity of Experimental Example 1 is approximately 2.5%, while that of Comparative Example 1 is approximately 3%. The difference in on-wafer coating uniformity between Experimental Example 1 and Comparative Example 1 is small, indicating that the on-wafer coating uniformity of Experimental Example 1 is not affected and can achieve the same level as conventional processes. Figure 5 The results show that the inter-wafer coating uniformity of Experimental Example 1 is 6.95%, while that of Comparative Example 1 is 6.45%. The difference in inter-wafer coating uniformity between Experimental Example 1 and Comparative Example 1 is small, and the inter-wafer coating uniformity of Experimental Example 1 is not affected, achieving the same level as conventional processes. Figure 6 The results show that the minority carrier lifetime of the battery in Experimental Example 1 is approximately 1950 μs, while that of the battery in Comparative Example 1 is approximately 2000 μs. The difference in minority carrier lifetime between Experimental Example 1 and Comparative Example 1 is small, indicating that the minority carrier lifetime of the battery in Experimental Example 1 is not affected and can reach the same level as conventional processes. Figure 7The open-circuit voltage of the battery in Experimental Example 1 is 720mV–730mV, while that of the battery in Comparative Example 1 is 723mV–728mV. The open-circuit voltages of Experimental Example 1 and Comparative Example 1 are very similar, indicating that the open-circuit voltage of the battery in Experimental Example 1 is unaffected and can achieve the same level as conventional processes. The passivation performance of the battery in Experimental Example 1 is also unaffected and can achieve the same level as conventional processes.

[0088] The batteries obtained in Experimental Example 2 and Comparative Example 2 were tested, including a coating rate test (see reference). Figure 8 ), In-film coating uniformity test (reference) Figure 9 Inter-film coating uniformity test (reference) Figure 10 Spoon life test (reference) Figure 11 ) and open-circuit voltage test (reference) Figure 12 ). Figure 8 The unit of the vertical axis is nm / min. Figure 11 The unit of the vertical axis is us. Figure 12 The unit of the vertical axis is mV. Figure 8 The results show that the coating rate of Experimental Example 2 was 7.5 nm / min, while the coating rate of Comparative Example 2 was 4 nm / min. The coating rate of Experimental Example 2 was significantly improved compared to that of Comparative Example 1. Figure 9 The results show that the on-wafer coating uniformity of Experimental Example 2 is approximately 4.5%, while that of Comparative Example 2 is approximately 5%. The difference in on-wafer coating uniformity between Experimental Example 2 and Comparative Example 2 is small, indicating that the on-wafer coating uniformity of Experimental Example 2 is not affected and can achieve the same level as conventional processes. Figure 10 The results show that the inter-wafer coating uniformity of Experimental Example 2 is 3.35%, while that of Comparative Example 2 is 3.49%. The difference in inter-wafer coating uniformity between Experimental Example 2 and Comparative Example 2 is small, and the inter-wafer coating uniformity of Experimental Example 2 is not affected, achieving the same level as conventional processes. Figure 11 The results show that the minority carrier lifetime of the battery in Experimental Example 2 is approximately 1500 μs, while that of the battery in Comparative Example 2 is approximately 1450 μs. The difference in minority carrier lifetime between Experimental Example 2 and Comparative Example 2 is small, indicating that the minority carrier lifetime of the battery in Experimental Example 2 is not affected and can reach the same level as conventional processes. Figure 12 The results show that the open-circuit voltage of the battery in Experimental Example 2 is approximately 722mV, and the open-circuit voltage of the battery in Comparative Example 2 is approximately 722mV. The open-circuit voltages of Experimental Example 2 and Comparative Example 2 are very similar, indicating that the open-circuit voltage of the battery in Experimental Example 2 is not affected and can reach the same level as conventional processes. The passivation performance of the battery in Experimental Example 2 is also unaffected and can reach the same level as conventional processes.

[0089] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A method for generating plasma, characterized in that, include: A plasma power supply is used to output pulse signals to the plasma generating component inside the processing cavity in order to generate plasma within the processing cavity; The pulse width of the pulse signal is 0.5ms-1ms, and the pulse interval is 4ms-7ms.

2. The plasma generation method according to claim 1, characterized in that, The pulse width is 0.55ms-0.8ms, and the pulse interval is 4.5ms-6.5ms.

3. The plasma generation method according to claim 2, characterized in that, The pulse width is 0.6 ms and the pulse interval is 6 ms.

4. The plasma generation method according to claim 1, characterized in that, The frequency of the pulse signal is 125Hz~250Hz.

5. The plasma generation method according to claim 1, characterized in that, The power corresponding to the pulse signal is 8KW~18KW.

6. The plasma generation method according to any one of claims 1 to 5, characterized in that, Also includes: Process gas is introduced into the processing chamber, and the plasma is formed by the process gas under the action of the pulse signal.

7. The plasma generation method according to claim 6, characterized in that, The process gases include reactive gases and protective gases.

8. The plasma generation method according to claim 7, characterized in that, The protective gas includes argon.

9. The plasma generation method according to any one of claims 1 to 5, characterized in that, The plasma power supply outputs pulse signals with a pulse width of 0.5ms-1ms and a pulse interval of 4ms-7ms to the plasma generating component inside the processing chamber, while simultaneously outputting pulse signals with a pulse width of 5ms-10ms and a pulse interval of 40ms-70ms.

10. The plasma generation method according to any one of claims 1 to 5, characterized in that, The plasma generation method includes an initial stage, an intermediate stage, and a final stage performed sequentially. In the initial stage, the pulse signal used has a pulse width of 0.5ms-1ms and a pulse interval of 4ms-7ms. In the intermediate stage, the pulse signal used has a pulse width of 5ms-10ms and a pulse interval of 40ms-70ms. In the final stage, the pulse signal used has a pulse width of 0.5ms-1ms and a pulse interval of 4ms-7ms.

11. The plasma generation method according to claim 10, characterized in that, Also includes: The process consists of a first overlapping stage between the initial stage and the intermediate stage, and a second overlapping stage between the intermediate stage and the final stage. In the first overlapping stage, the plasma power supply outputs a pulse signal with a pulse width of 0.5ms-1ms and a pulse interval of 4ms-7ms to the plasma generating component inside the processing cavity, while simultaneously outputting a pulse signal with a pulse width of 5ms-10ms and a pulse interval of 40ms-70ms. In the second overlapping stage, the plasma power supply outputs a pulse signal with a pulse width of 0.5ms-1ms and a pulse interval of 4ms-7ms to the plasma generating component inside the processing cavity, while simultaneously outputting a pulse signal with a pulse width of 5ms-10ms and a pulse interval of 40ms-70ms.

12. A processing method, characterized in that, include: The plasma obtained by the plasma generation method according to any one of claims 1 to 11 is subjected to plasma treatment in the processing chamber.

13. The processing method according to claim 12, characterized in that, The plasma treatment is a coating process, in which a process film is deposited by using the obtained plasma within the processing chamber.

14. The processing method according to claim 13, characterized in that, The deposition rate of the process film is 7 nm / min-15 nm / min.

15. The processing method according to claim 13, characterized in that, The coating process includes plasma-enhanced chemical vapor deposition or plasma-enhanced atomic layer deposition.

16. The processing method according to claim 13, characterized in that, The material of the process film includes silicon-based materials.

17. The processing method according to claim 16, characterized in that, The material of the process film is silicon nitride; the coating process is plasma-enhanced chemical vapor deposition; the parameters of the coating process also include: the reaction gases used include SiH4 and NH3, the flow rate of SiH4 is 760sccm~780sccm, the flow rate of NH3 is 5500sccm~6500sccm, the chamber pressure in the processing chamber is 200Pa~220Pa, the power of the pulse signal is 10KW~15KW, and the temperature is 460℃~520℃.

18. The processing method according to claim 17, characterized in that, The parameters for the coating process also include: using a protective gas, with a flow rate ratio of 1:8 to 1:20 between the protective gas and the reactive gas.

19. The processing method according to claim 16, characterized in that, The material of the process film is amorphous silicon; the coating process is plasma-enhanced chemical vapor deposition; the parameters of the coating process also include: the reaction gases used include SiH4 and Ar, the flow rate of SiH4 is 1800 sccm~2200 sccm, the flow rate of Ar is 9400 sccm~9800 sccm, the chamber pressure in the processing chamber is 230 Pa~250 Pa, the power of the pulse signal is 8 kW~12 kW, and the temperature is 410 ℃~430 ℃.

20. The processing method according to claim 19, characterized in that, The parameters of the coating process also include: using a protective gas, with a flow rate ratio of protective gas to reactive gas of 4:1 to 8:

1.

21. The processing method according to claim 13, characterized in that, The process film is used as a passivation film on the back of the PERC battery; the coating process includes: sequentially forming a first sub-process film and a second sub-process film in the same processing chamber, wherein the material of the first sub-process film includes aluminum oxide and the material of the second sub-process film includes silicon nitride.

22. The processing method according to claim 13, characterized in that, The coating process is a plasma-enhanced atomic layer deposition process; the plasma-enhanced atomic layer deposition process includes several sub-cycle depositions; in each sub-cycle deposition, the plasma power supply outputs the pulse signal to the plasma generating component inside the processing cavity.

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