Passivation contact structure of boron and phosphorus doped Poly layer and battery thereof

Abstract

The invention discloses a passivation contact structure of a boron and phosphorus doped Poly layer and a battery thereof. According to the passivation contact structure, a tunneling oxide layer with two thin and compact sides and a thick and loose middle grows on the surface of a silicon wafer in a mode of combining low-temperature and low-pressure oxidation, high-temperature and normal-pressure oxidation and low-temperature and normal-pressure oxidation. According to the invention, through superposition of the oxide layers with different compactness, the overall thickness of the tunneling oxide layer is improved, so that the structure of the tunneling oxide layer is not obviously damaged in the subsequent boron and phosphorus diffusion process, and the passivation effect of the boron and phosphorus doped Poly layer is obviously improved. According to the method, the Poly silicon layers and the doped polycrystalline silicon layers with different thicknesses can be obtained, and the method can be applied to all batteries needing to use boron Poly and phosphorus Poly.

Description

[0001] The present application is a divisional application of the Chinese invention patent with the application number 202510712254.4, the application date May 30, 2025, and the invention name of a passivation method of boron and phosphorus doped Poly layer, a passivation contact structure thereof, and a battery. TECHNICAL FIELD

[0002] The present application belongs to the technical field of solar cells, and particularly relates to a passivation contact structure of a boron and phosphorus doped Poly layer and a battery thereof. BACKGROUND

[0003] When the solar cell is irradiated by sunlight, two kinds of carriers, i.e. electrons with negative charges and holes with positive charges, are excited inside the solar cell. During the production of the solar cell, defects inside the solar cell and interface state densities of each surface need to be reduced as much as possible to enhance the passivation effect, so as to reduce the recombination of the electrons and holes inside the solar cell, reduce internal consumption, and make more carriers reach the positive and negative electrodes of the solar cell as much as possible, thereby increasing the photoelectric conversion efficiency of the solar cell.

[0004] In the manufacturing of the solar cell, boron and phosphorus doped Poly (polysilicon structure with boron and phosphorus doped tunneling oxide layer) passivation is a common surface treatment method.

[0005] For boron diffusion on N-type silicon, the boron atoms entering the single crystal silicon substrate form a PN junction between the N-type silicon substrate. The passivation mechanism is that the PN junction can screen the holes passing through the PN junction, while blocking the electrons passing through, so as to form an environment in which the number of holes is dominant on one side of the PN junction, and the number of electrons is dominant on the other side, thereby reducing the recombination of holes and electrons at defects. In addition, there are a large number of defects at the junction between the single crystal silicon and the Poly layer, and the growth of a dense tunneling oxide layer in the middle of the two interfaces can significantly reduce the interface state density, so that the recombination of holes passing through the tunneling oxide layer is small, and the tunneling oxide layer and the PN junction work together to make the boron Poly have good passivation effect. Generally, the passivation effect is represented by the recombination current density (the size of the recombination current per unit area), and the smaller the recombination current density, the better the surface passivation effect.

[0006] The passivation mechanism of the phosphorus doped Poly layer is similar to that of the boron doped Poly layer. There is a high concentration of phosphorus atoms in the Poly layer, and a part of the phosphorus atoms will pass through the tunneling oxide layer to form a high-low junction structure with the N-type substrate, and cause the energy band to bend near the tunneling oxide layer. On the one hand, the number of minority carriers (holes) near the tunneling oxide layer is reduced, and the recombination is reduced. On the other hand, the majority carriers (electrons) can be selectively screened to pass through the tunneling oxide layer, thereby greatly enhancing the passivation effect.

[0007] At present, the passivation method commonly used for boron and phosphorus doped Poly layer is to put the silicon wafer into a quartz furnace tube, and oxygen is introduced at a temperature above 600 DEG C to directly react with silicon on the surface of the silicon wafer to form a 1-2 nm thick silicon oxide film (tunneling oxide layer). Then, a Poly silicon layer (polysilicon layer) is deposited directly on the tunneling oxide layer. Then, the silicon wafer is put into a high-temperature diffusion furnace tube for deposition and oxidation promotion steps. Finally, the silicon wafer is cooled to room temperature to obtain the required boron Poly or phosphorus Poly structure. However, the passivation effect of the Poly obtained by this method is not good, and the recombination current density is high. Especially, the recombination current density of boron Poly is as high as 15fA / cm 2 Moreover, the passivation effect is not good when the boron and phosphorus doped Poly layer is directly grown at high temperature to form a loose tunneling oxide layer. When the boron and phosphorus doping concentration is high, it is easy to cause serious internal expansion, and the process is greatly affected, so that a better morphology structure cannot be formed. Therefore, this method cannot meet the requirements of the complex structure of the battery (such as BC structure battery) which is processed on the Poly layer. SUMMARY

[0008] In view of the problem of poor passivation effect of boron and phosphorus doped Poly layer caused by direct high-temperature growth of tunneling oxide layer, the purpose of the present application is to provide a passivation method for boron and phosphorus doped Poly layer based on LPCVD process optimization, and a passivation contact structure and battery.

[0009] The present application achieves the technical effects by the following technical solutions.

[0010] In a first aspect, the present application provides a passivation method for boron and phosphorus doped Poly layer, which comprises the following steps:

[0011] S1, providing a clean and polished silicon wafer, using an LPCVD device, vacuumizing, introducing oxygen, and oxidizing the silicon wafer at a low temperature below 600 DEG C to grow a first oxide layer with a thickness of 0.3-0.8 nm and a density on the surface of the silicon wafer;

[0012] S2, increasing the temperature by 50-220 DEG C of step 1, continuously introducing oxygen, and oxidizing the silicon wafer at a pressure greater than or equal to 1 atm to grow a second oxide layer with a thickness of 0.5-1 nm and a loose density on the surface of the silicon wafer;

[0013] S3, stopping the introduction of oxygen, keeping the pressure unchanged, and reducing the temperature to below 600 DEG C to oxidize the silicon wafer for a third time to grow a third oxide layer with a thickness of 0.1-0.4 nm and a density on the surface of the silicon wafer; thus, a tunneling oxide layer structure with loose middle and dense sides is grown on the surface of the silicon wafer;

[0014] S4, continue to use LPCVD equipment, the temperature of step S3 is increased by 0~50℃, vacuum is extracted, and then silane is introduced, a polysilicon layer is deposited on the first oxide layer under high temperature and low pressure until the process required film thickness is reached;

[0015] S5, a high temperature diffusion tube is used to perform boron atom or phosphorus atom deposition and oxidation promotion, so that a certain concentration of boron or phosphorus is doped in the polysilicon layer to form a doped polysilicon layer.

[0016] Preferably, in step S1, the temperature is 400~590℃, the pressure is 0.1~0.5 standard atmosphere, and the first oxidation time is 10~20 minutes.

[0017] Further, in step S2, the temperature is 610~640℃, the pressure is normal pressure, and the second oxidation time is 10~20 minutes.

[0018] Further, in step S3, the temperature is 550~590℃, the pressure is normal pressure, and the third oxidation time is 10~20 minutes.

[0019] Further, in step S4, the temperature is 550~640℃, and the vacuum pressure is 180~300mTorr.

[0020] Further, the silicon wafer is an N-type silicon wafer or a P-type silicon wafer.

[0021] Further, in steps S1 and S2, the flow rate of the introduced oxygen is 5~30L / min.

[0022] In step S5, in the process of boron atom deposition and oxidation promotion (boron diffusion), the deposition temperature is 800~850℃, the oxidation promotion temperature is 940~1000℃, and the optimal oxidation promotion temperature is 960℃; in the process of phosphorus atom deposition and oxidation promotion (phosphorus diffusion), the deposition temperature is 800~850℃, and the oxidation promotion temperature is 880~920℃. The combination of low-temperature and low-pressure oxidation, high-temperature and normal-pressure oxidation, and low-temperature and normal-pressure oxidation is used to grow the tunnel oxide layer, which is less affected by the fluctuation of the boron and phosphorus diffusion and oxidation temperature, and can almost accept a fluctuation of 30℃ from the optimal oxidation promotion temperature.

[0023] In a second aspect, the present application provides a passivation contact structure of a boron and phosphorus doped Poly layer, which comprises a first oxide layer, a second oxide layer, a third oxide layer and a doped polysilicon layer grown on a silicon wafer by the aforementioned passivation method, the doped polysilicon layer is on the first oxide layer, the first oxide layer, the second oxide layer and the third oxide layer form a tunneling oxide layer, the second oxide layer is in the middle of the tunneling oxide layer and is thick and loose; the first oxide layer and the third oxide layer are on both sides of the tunneling oxide layer and are thin and dense.

[0024] In a third aspect, the present application provides a battery with a passivation contact structure of a boron and phosphorus doped Poly layer, which comprises a silicon wafer and a passivation contact structure as described above formed on the surface of the silicon wafer.

[0025] Further, the battery is a TOPCon battery, a TBC battery or a perovskite stacked battery.

[0026] Compared with the prior art, the present application has the following beneficial effects.

[0027] The present application grows a tunneling oxide layer by combining low-temperature and low-pressure oxidation, high-temperature and normal-pressure oxidation and low-temperature and normal-pressure oxidation, the film layer structure of the generated tunneling oxide layer is a laminated structure with thin and dense layers on both sides and a thick and loose layer in the middle, and the passivation effect of the boron and phosphorus doped Poly layer structure is improved by the superposition of different dense oxide layers.

[0028] The oxide layers on both sides are grown at low temperature, and the interface defects between the Poly silicon layer and the oxide layers are few, which can significantly reduce the interface state density between the oxide layer and the silicon, reduce the recombination of carriers reaching the interface, and significantly improve the passivation effect.

[0029] At the same time, the second oxide layer is grown at high temperature, the film layer is thick and loose, which not only can improve the overall thickness of the tunneling oxide layer (but the thickness of the three-layer oxide layer is roughly equal to the thickness of the conventional tunneling oxide layer), but also can provide a channel for impurity atoms to pass through the tunneling oxide layer to form a PN junction in the subsequent boron diffusion (doping) and / or phosphorus diffusion (doping) process, so that the tunneling oxide layer is exempted from significant damage, thereby further improving the passivation effect.

[0030] Compared with the boron and phosphorus doped Poly layer by the conventional direct high-temperature oxidation process, the minority carrier lifetime, iVoc, iFF and PL brightness are all significantly improved by using the passivation method of the present application, and the recombination current density J0 is significantly reduced, which shows a good passivation effect.

[0031] The application can obtain a better passivation effect by optimizing the pressure, temperature, time and other parameters of the LPCVD device, and the required structure can be obtained by one process, compared with other passivation methods such as annealing, hydrogen injection and adding a stack of different materials, the process time is short, the use of special gas is less, and the production cost can be effectively reduced.

[0032] The passivation contact structure of the application has good robustness, so that when the temperature and airflow of the high-temperature furnace tube have small fluctuations during the use of the LPCVD device, the passivation effect of the boron and phosphorus doped Poly layer will not be obviously affected. The tunneling oxide layer grown by the application is less affected by the fluctuation of the boron and phosphorus diffusion oxidation temperature, and can accept a fluctuation of 30 DEG C at the optimum oxidation promotion temperature.

[0033] The passivation contact structure of the application is applied to the preparation of a battery (such as a BC structure battery) which needs to perform secondary processing on the boron and phosphorus doped Poly layer to form a complex structure, and the subsequent laser process will not have a great influence on the tunneling oxide layer structure, and the plane after wet etching is more flat, and a better topography structure can be formed.

[0034] The application can obtain a Poly silicon layer and a doped polysilicon layer with different thicknesses, and the passivation performance of the boron or phosphorus doped Poly layer is excellent, and can be applied to all batteries which need to use boron Poly and phosphorus Poly. BRIEF DESCRIPTION OF DRAWINGS

[0035] In order to more clearly illustrate the technical solutions of the embodiments of the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only some embodiments of the application, and those skilled in the art can obtain other drawings according to these drawings without any creative effort.

[0036] Figure 1 It is a schematic diagram of the passivation contact structure of the application.

[0037] Figure 2 It is a depth-concentration comparison diagram of the boron doped Poly layer of the application and the prior art.

[0038] Figure 3 It is a schematic diagram of the TOPCon battery structure.

[0039] Figure 4 It is a schematic diagram of the TBC battery structure.

[0040] Figure 5 It is a depth-concentration comparison diagram of the boron doped Poly layer after laser film removal and cleaning film removal.

[0041] Figure 6The back scanning electron microscope image of the BC structure battery prepared by using the passivation method of the present application.

[0042] In the figure: 1-silicon wafer, 2-first oxide layer, 3-second oxide layer, 4-third oxide layer, 5-doped polysilicon layer. DETAILED DESCRIPTION

[0043] In order to make the technical problems, technical solutions and beneficial effects solved by the present application more clear, the present application is further described in detail below in combination with the drawings and specific embodiments. It should be understood that the embodiments described herein are part of the embodiments of the present application, rather than all the embodiments, and are only used to explain the present application, and do not limit the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor are within the protection scope of the present application.

[0044] In a first aspect, the present application provides a passivation method for a boron and phosphorus doped Poly layer, comprising the following steps:

[0045] S1, providing a clean and polished silicon wafer, using an LPCVD device, vacuumizing, and continuously feeding oxygen, at a low temperature below 600℃ and low pressure, to perform first oxidation on the silicon wafer, and grow a thin and dense first oxide layer on the surface of the silicon wafer;

[0046] S2, increasing the temperature of step S1 by 50-220℃, continuously feeding oxygen, and performing second oxidation on the silicon wafer at a pressure greater than or equal to 1 standard atmosphere, to continue growing a thick and loose second oxide layer on the surface of the silicon wafer;

[0047] S3, stopping feeding oxygen, keeping the pressure unchanged, and reducing the temperature to below 600℃, to perform third oxidation on the silicon wafer, and continue growing a thin and dense third oxide layer on the surface of the silicon wafer; thus, a tunneling oxide layer structure with loose middle and dense sides is grown on the surface of the silicon wafer;

[0048] S4, continuing to use the LPCVD device, increasing the temperature of step S3 by 0-50℃, vacuumizing and then feeding silane, and depositing a Poly silicon layer on the first oxide layer at high temperature and low pressure until the required film thickness is reached;

[0049] S5, using a high-temperature diffusion tube to deposit and oxidize boron atoms or phosphorus atoms, to dope a certain concentration of boron or phosphorus in the Poly silicon layer, and form a doped polysilicon layer.

[0050] As a preferred embodiment, in step S1, the temperature is 400-590℃, the pressure is 0.1-0.5 standard atmosphere, the first oxidation time is 10-20 minutes, and the thickness of the first oxide layer is 0.3-0.8 nm. Specifically, the first oxidation temperature can be 400℃, 430℃, 460℃, 490℃, 500℃, 520℃, 550℃, 570℃ or 590℃, etc., and is further preferably 500-580℃. The first oxidation time can be 10 minutes, 14 minutes, 16 minutes, 18 minutes or 20 minutes, etc. The thickness of the first oxide layer can be 0.3 nm, 0.4 nm, 0.5 nm, 0.6 nm, 0.7 nm or 0.8 nm, etc., and is further preferably 0.3-0.5 nm. In this way, a thin and dense tunnel oxide layer can be generated by low-temperature and low-pressure oxidation.

[0051] As a preferred embodiment, in step S2, the temperature is 610-640℃, the pressure is normal pressure, the second oxidation time is 10-20 minutes, and the thickness of the second oxide layer is 0.5-1 nm. Specifically, the second oxidation temperature can be 610℃, 620℃, 625℃, 632℃ or 640℃, etc. The second oxidation time can be 10 minutes, 14 minutes, 16 minutes, 18 minutes or 20 minutes, etc. The thickness of the second oxide layer can be 0.5 nm, 0.6 nm, 0.7 nm, 0.8 nm, 0.9 nm or 1 nm, etc. In this way, a thick and loose tunnel oxide layer can be generated by high-temperature and normal-pressure oxidation.

[0052] As a preferred embodiment, in step S3, the temperature is 550-590℃, the pressure is normal pressure, the third oxidation time is 10-20 minutes, and the thickness of the third oxide layer is 0.1-0.4 nm. Specifically, the third oxidation temperature can be 550℃, 560℃, 570℃, 580℃ or 590℃, etc. The third oxidation time can be 10 minutes, 14 minutes, 16 minutes, 18 minutes or 20 minutes, etc. The thickness of the third oxide layer can be 0.1 nm, 0.18 nm, 0.25 nm, 0.3 nm, 0.35 nm or 0.4 nm, etc. In this way, a thin and dense tunnel oxide layer can be generated by low-temperature and normal-pressure oxidation.

[0053] As a preferred embodiment, in step S4, the temperature is 550-640℃, specifically, it can be 550℃, 560℃, 570℃, 580℃, 590℃, 600℃, 610℃, 620℃, 630℃ or 640℃, etc.; the vacuum pressure is 180-300 mTorr, specifically, it can be 180 mTorr, 200 mTorr, 220 mTorr, 250 mTorr, 280 mTorr or 300 mTorr, etc. In this way, the Poly silicon layer with different thickness can be deposited on the tunneling oxide layer.

[0054] As a preferred embodiment, the silicon wafer is an N-type silicon wafer or a P-type silicon wafer. The passivation method of the present application is not only suitable for the N-type silicon wafer, but also suitable for the P-type silicon wafer.

[0055] As a preferred embodiment, in steps S1 and S2, the flow rate of the oxygen introduced is 5-30 L / min, so that the required oxide layer thickness for forming the passivation contact can be met.

[0056] The oxygen flow rate can control the time for the furnace tube to change from vacuum to normal pressure. The low-pressure oxidation is similar to the low-temperature oxidation in nature, both of which can form a more dense tunneling oxide layer. In step S1, the oxygen is preferably introduced slowly to allow it to grow at low temperature and low pressure.

[0057] In step S3, the oxygen is not introduced, and the existing oxygen in the tube is used for continuous oxidation.

[0058] As a preferred embodiment, in the deposition and oxidation promotion process of boron atoms (boron diffusion), the deposition temperature is 800-850℃, and the oxidation promotion temperature is 940-1000℃, and the optimal oxidation promotion temperature is 960℃; in the deposition and oxidation promotion process of phosphorus atoms (phosphorus diffusion), the deposition temperature is 800-850℃, and the oxidation promotion temperature is 880-920℃.

[0059] Specifically, in the boron diffusion process, boron trichloride and oxygen are introduced, first deposited at 800-850℃ for 600-1500 seconds, then heated to 940-1000℃, and then more oxygen is continuously introduced for promotion for more than 20 minutes. In the phosphorus diffusion process, phosphorus oxychloride and oxygen are introduced, first deposited at 800-850℃ for 600-1500 seconds, then heated to 880-920℃, and then more oxygen is continuously introduced for promotion for 10-20 minutes. The specific deposition amount, oxidation time and temperature mainly depend on the LP process.

[0060] The oxidation promotion temperature has a great influence on the diffusion. However, the tunneling oxide layer is grown by the method of low-temperature and low-pressure oxidation, high-temperature and normal-pressure oxidation, and low-temperature and normal-pressure oxidation in combination in the present application, so the influence of the boron and phosphorus diffusion temperature fluctuations on the latter is small, and it can be accepted that the fluctuation is within 30℃ of the optimal oxidation promotion temperature.

[0061] After heteroatom diffusion, the doping concentration at different depths of the silicon wafer can be obtained using an ECV testing machine. Figure 2 As can be seen from the comparison, compared with the boron-doped Poly layer of the tunnel oxide layer grown at high temperature in the prior art, the present invention can reduce the inward expansion (the faster the decrease, the smaller the inward expansion) while obtaining a higher doping concentration, thereby improving the passivation performance.

[0062] Secondly, the present invention provides a passivated contact structure for a boron- and phosphorus-doped Poly layer, such as... Figure 1 As shown, the passivated contact structure includes a first oxide layer 2, a second oxide layer 3, a third oxide layer 4, and a doped polysilicon layer 5 grown on the silicon wafer 1 using the aforementioned passivation method. The doped polysilicon layer 5 is above the first oxide layer 2. The first oxide layer 2, the second oxide layer 3, and the third oxide layer 4 constitute a tunneling oxide layer. The second oxide layer 3 is located in the middle of the tunneling oxide layer and is thick and porous. The first oxide layer 2 and the third oxide layer 4 are located on both sides of the tunneling oxide layer and are thin and dense.

[0063] Thirdly, the present invention provides a battery having a passivated contact structure with a boron- and phosphorus-doped Poly layer, the battery comprising a silicon wafer and a passivated contact structure as described above formed on the surface of the silicon wafer.

[0064] As a preferred embodiment, the battery is a TOPCon battery, a TBC battery, or a perovskite tandem battery.

[0065] The passivation method of this invention can obtain polysilicon layers and doped polycrystalline silicon layers of different thicknesses as required. Boron and phosphorus-doped polysilicon layers exhibit excellent passivation performance and can be applied to all batteries requiring the use of boron-doped or phosphorus-doped polysilicon. For example... Figure 3 As shown, the passivation method of this invention can grow a tunneling oxide layer structure with a loose middle and dense sides in the N region of the TOPCon cell structure, and deposit a Poly silicon layer and an NPoly layer formed by boron or phosphorus doping to form a doped polycrystalline silicon layer. Figure 4 As shown, the passivation method of the present invention can grow a tunneling oxide layer structure with a loose middle and dense sides in the N and P regions of the TBC battery structure, and deposit a Poly silicon layer and an NPoly layer and a PPoly layer formed by boron or phosphorus doping to form a doped polycrystalline silicon layer.

[0066] For structures such as BC cells that require further processing of the boron-doped Poly layer structure, the tunneling oxide layer grown in this invention can effectively resist the influence of laser on the boron-doped Poly layer. Figure 5The concentration-depth curves of the two BSG film removing methods of laser film removing and cleaning film removing are shown, from which it can be seen that the laser process does not have obvious influence on the subsequent internal diffusion of boron atoms. Meanwhile, the uniform tunneling oxide film layer is easier to form a more flat surface in the subsequent wet etching process. The BC structure battery prepared by using the passivation method of the application can have Figure 6 The back scanning electron microscope image can observe that the P region, the N region and the Gap region with good flatness can be formed by using the passivation method of the application.

[0067] The specific embodiments of the application will be further explained by the following examples and comparative examples.

[0068] The reagents, materials and instruments used in the following description are all conventional reagents, conventional materials and conventional instruments, which can be commercially available. The methods in the examples are all conventional methods in the art, unless otherwise specified.

[0069] Example 1

[0070] The passivation method of the boron-doped Poly layer provided by the application comprises the following steps.

[0071] S1, prepare an N-type silicon wafer 1 with a resistivity of 10Ω·cm and a thickness of 180μm, polish both sides, clean, and put into an LPCVD device, vacuumize to near vacuum state, slowly heat the furnace tube to 570℃, slowly pass oxygen into the furnace tube at a flow rate of 10L / min, and keep the pressure in the furnace tube below 0.5 standard atmosphere during the heating process, and perform first oxidation on the silicon wafer in a low-temperature and low-pressure environment for 15 minutes, and grow a 0.4nm-thick dense first oxide layer 2 on the surface of the silicon wafer 1.

[0072] S2, continue to pass oxygen, the pressure in the furnace tube is 1 standard atmosphere, and the temperature in the furnace tube is increased to 630℃, and perform second oxidation on the silicon wafer in a high-temperature and normal-pressure environment for 12 minutes, and continue to grow a 0.8nm-thick relatively loose second oxide layer 3 on the surface of the silicon wafer 1.

[0073] S3, stop passing oxygen, keep the pressure in the furnace tube unchanged, and reduce the temperature to 580℃, and perform third oxidation on the silicon wafer in a low-temperature and normal-pressure environment for 12 minutes, and continue to grow a 0.2nm-thick relatively dense third oxide layer 4 on the surface of the silicon wafer 1; thus, the tunneling oxide layer structure with loose middle and dense sides is grown on the surface of the silicon wafer.

[0074] S4, continue to use the LPCVD device, control the temperature in the furnace tube at 600℃, and after vacuumizing, pass in silane, the vacuum pressure is 200mTorr, deposit a Poly silicon layer on the first oxide layer 2 in a high-temperature and low-pressure environment, until the required film thickness of the process is reached.

[0075] S5, using high temperature diffusion tube for boron atom deposition and oxidation, into the boron chloride and oxygen, first at 830 ℃ deposition 1000 seconds, then heated to 960 ℃, continue to pass more oxygen to promote 22 minutes, so that the Poly silicon layer doped with a certain concentration of boron, forming a doped polysilicon layer 5.

[0076] Examples 2~4

[0077] Examples 2~4 include most of the operation steps in Example 1, the difference is that the temperature, pressure, time, oxidation layer thickness, doped atoms of three times of oxidation. Specifically as follows.

[0078] Example 2

[0079] The passivation method of boron-doped Poly layer provided by the application comprises the following steps.

[0080] S1, prepare a N-type silicon wafer with a resistivity of 1Ω·cm and a thickness of 130μm, polish both sides, clean, put into the LPCVD device, vacuum to near vacuum state, slowly heat the furnace tube to 500℃, slowly pass oxygen into the furnace tube at a flow rate of 5L / min, keep the pressure in the furnace tube below 0.3 standard atmosphere during the heating process, oxidize the silicon wafer for the first time in a low temperature and low pressure environment for 10 minutes, and grow a dense first oxide layer with a thickness of 0.3nm on the surface of the silicon wafer.

[0081] S2, continue to pass oxygen, the pressure in the furnace tube is 1 standard atmosphere, the temperature in the furnace tube is raised to 610℃, the silicon wafer is oxidized for the second time in a high temperature and normal pressure environment for 10 minutes, and a relatively loose second oxide layer with a thickness of 0.5nm is continuously grown on the surface of the silicon wafer.

[0082] S3, continue to pass oxygen, keep the pressure in the furnace tube unchanged, reduce the temperature to 550℃, oxidize the silicon wafer for the third time in a low temperature and normal pressure environment for 10 minutes, and a relatively dense third oxide layer with a thickness of 0.2nm is continuously grown on the surface of the silicon wafer; by this time, a tunneling oxide layer structure with loose middle and dense sides is grown on the surface of the silicon wafer.

[0083] S4, continue to use the LPCVD device, control the temperature in the furnace tube at 550℃, pass in silane, and at the same time, vacuum, the vacuum pressure is 180mTorr, deposit a Poly silicon layer on the first oxide layer in a high temperature and low pressure environment, until the required film thickness of the process is reached.

[0084] S5, using high temperature diffusion tube boron atom deposition and oxidation, into the boron chloride and oxygen, first at 810 DEG C deposition 1200 seconds, then heated to 990 DEG C, continue to pass more oxygen to promote 30 minutes, make Poly silicon layer doped with a certain concentration of boron, form doped polysilicon layer.

[0085] Example 3

[0086] The passivation method of the phosphorus-doped Poly layer provided by the application comprises the following steps.

[0087] S1, prepare a N-type silicon wafer with a resistivity of 20 Ω·cm and a thickness of 220 μm, polish both sides, clean, put into the LPCVD device, vacuum to near vacuum state, slowly heat the furnace tube to 580 DEG C, slowly pass oxygen into the furnace tube at a flow rate of 20 L / min, keep the pressure in the furnace tube below 0.5 atm during the heating process, perform first oxidation on the silicon wafer in a low-temperature and low-pressure environment for 20 minutes, and grow a 0.8 nm-thick dense first oxide layer on the surface of the silicon wafer.

[0088] S2, continue to pass oxygen, the pressure in the furnace tube is 1 atm, raise the temperature in the furnace tube to 640 DEG C, perform second oxidation on the silicon wafer in a high-temperature and normal-pressure environment for 20 minutes, and continue to grow a 1 nm-thick relatively loose second oxide layer on the surface of the silicon wafer.

[0089] S3, continue to pass oxygen, keep the pressure in the furnace tube unchanged, reduce the temperature to 590 DEG C, perform third oxidation on the silicon wafer in a low-temperature and normal-pressure environment for 20 minutes, and continue to grow a 0.4 nm-thick relatively dense third oxide layer on the surface of the silicon wafer; at this time, a tunneling oxide layer structure with loose middle and dense sides is grown on the surface of the silicon wafer.

[0090] S4, continue to use the LPCVD device, control the temperature in the furnace tube at 640 DEG C, after vacuum, pass in silane, the vacuum pressure is 300 mTorr, deposit a Poly silicon layer on the first oxide layer in a high-temperature and low-pressure environment, until the film thickness required by the process is reached.

[0091] S5, using high temperature diffusion tube phosphorus atom deposition and oxidation, pass in phosphorus oxychloride and oxygen, first at 850 DEG C deposition 600 seconds, then heated to 920 DEG C, continue to pass more oxygen to promote 10 minutes, make Poly silicon layer doped with a certain concentration of phosphorus, form doped polysilicon layer.

[0092] Example 4

[0093] The passivation method of the phosphorus-doped Poly layer provided by the application comprises the following steps.

[0094] S1, prepare a piece of N-type silicon wafer with resistivity of 12 Ω-cm and thickness of 200 μm, polish both sides, clean, put into LPCVD equipment, vacuum to near vacuum state, slowly heat the furnace tube to 580 ℃, slowly pass oxygen into the furnace tube at a flow rate of 30 L / min, keep the pressure in the furnace tube below 0.3 atm during the heating process, oxidize the silicon wafer for the first time in a low-temperature and low-pressure environment for 13 min, and grow a 0.5 nm thick dense first oxide layer on the surface of the silicon wafer.

[0095] S2, continue to pass oxygen, the pressure in the furnace tube is 1 atm, raise the temperature in the furnace tube to 620 ℃, oxidize the silicon wafer for the second time in a high-temperature and normal-pressure environment for 15 min, and continue to grow a 0.9 nm thick relatively loose second oxide layer on the surface of the silicon wafer.

[0096] S3, stop passing oxygen, keep the pressure in the furnace tube unchanged, reduce the temperature to 570 ℃, oxidize the silicon wafer for the third time in a low-temperature and normal-pressure environment for 14 min, and continue to grow a 0.25 nm thick relatively dense third oxide layer on the surface of the silicon wafer; thus, a tunnel oxide layer structure with loose middle and dense sides is grown on the surface of the silicon wafer.

[0097] S4, continue to use the LPCVD equipment, control the temperature in the furnace tube at 620 ℃, pass silane after vacuum, the vacuum pressure is 240 mTorr, deposit a polysilicon layer on the first oxide layer in a high-temperature and low-pressure environment, until the required film thickness is reached.

[0098] S5, use a high-temperature diffusion tube to deposit and oxidize phosphorus atoms, pass phosphorus oxychloride and oxygen, first deposit at 800 ℃ for 1500 s, then raise the temperature to 880 ℃, continue to pass more oxygen to promote for 20 min to dope a certain concentration of phosphorus in the polysilicon layer, forming a doped polysilicon layer.

[0099] Comparative Example 1

[0100] The difference between Comparative Example 1 and Examples 1 and 2 is that a conventional direct high-temperature growth tunnel oxide layer is used, as follows.

[0101] S1, prepare a piece of N-type silicon wafer with resistivity of 10 Ω-cm and thickness of 180 μm, polish both sides, clean, put into LPCVD equipment, vacuum, after waiting for the furnace tube to slowly heat to 620 ℃, pass oxygen at a flow rate of 36 L / min, return the furnace tube to normal pressure, and oxidize the silicon wafer at the same time, growing a 2 nm thick tunnel oxide layer on the surface of the silicon wafer.

[0102] S2, continue to use LPCVD equipment, the temperature in the furnace tube is controlled at 600°C, after vacuum, silane is introduced, the vacuum pressure is 200 mTorr, and a polysilicon layer is deposited on the tunneling oxide layer.

[0103] S3, boron atom deposition and oxidation promotion are carried out by using a high-temperature diffusion tube, boron trichloride and oxygen are introduced, 1000 seconds are deposited at 830°C, then the temperature is increased to 960°C, more oxygen is continuously introduced for 22 minutes, a certain concentration of boron is doped in the polysilicon layer, and a doped polysilicon layer is formed.

[0104] Comparative Example 2

[0105] The difference between Comparative Example 2 and Examples 3 and 4 lies in that a direct high-temperature growth tunneling oxide layer is used, and the specific process is as follows.

[0106] S1, an N-type silicon wafer with a resistivity of 20Ω·cm and a thickness of 220μm is prepared, both sides are polished, cleaned, and placed in an LPCVD equipment, vacuum is drawn, and after the furnace tube is heated to 610°C, oxygen with a flow rate of 36L / min is introduced, the furnace tube is returned to normal pressure, and the silicon wafer is oxidized, a 1.6nm tunneling oxide layer is grown on the surface of the silicon wafer.

[0107] S2, continue to use LPCVD equipment, the temperature in the furnace tube is controlled at 615°C, after vacuum, silane is introduced, the vacuum pressure is 300 mTorr, and a polysilicon layer is deposited on the tunneling oxide layer in a high-temperature low-pressure environment until the film thickness required by the process is reached.

[0108] S3, phosphorus atom deposition and oxidation promotion are carried out by using a high-temperature diffusion tube, phosphorus oxychloride and oxygen are introduced, 600 seconds are deposited at 850°C, then the temperature is increased to 920°C, more oxygen is continuously introduced for 10 minutes, a certain concentration of phosphorus is doped in the polysilicon layer, and a doped polysilicon layer is formed.

[0109] Comparative Example 3

[0110] The difference between Comparative Example 3 and Examples 1 and 2 lies in that a two-layer structure tunneling oxide layer is grown by low-temperature low-pressure oxidation and high-temperature normal-pressure oxidation, and the specific process is as follows.

[0111] S1, an N-type silicon wafer with a resistivity of 10Ω·cm and a thickness of 180μm is prepared, both sides are polished, cleaned, and placed in an LPCVD equipment, vacuum is drawn, and after the furnace tube is heated to 570°C, oxygen with a flow rate of 10L / min is introduced, the pressure in the furnace tube is maintained below 0.5 standard atmospheres during the heating process, and the silicon wafer is oxidized for the first time for 15 minutes in a low-temperature low-pressure environment, a 0.4nm thick dense oxide layer is grown on the surface of the silicon wafer.

[0112] S2, continue to pass in oxygen, the pressure in the furnace tube is 1 atmosphere, the temperature in the furnace tube is increased to 630°C, the silicon wafer is oxidized for 12 minutes under high temperature and normal pressure, and a 0.8 nm thick loose oxide layer is continuously grown on the surface of the silicon wafer; thus, a tunneling oxide layer structure with a loose inner side and a dense outer side is grown on the surface of the silicon wafer.

[0113] S3, continue to use the LPCVD device, the temperature in the furnace tube is controlled at 600°C, silane is passed in after vacuumizing, the vacuum pressure is 200 mTorr, and a polysilicon layer is deposited on the first oxide layer 2 under high temperature and low pressure.

[0114] S4, boron atom deposition and oxidation promotion are performed by using a high-temperature diffusion tube, boron trichloride and oxygen are passed in, deposition is performed at 830°C for 1000 seconds, the temperature is increased to 960°C, more oxygen is continuously passed in for 22 minutes, a certain concentration of boron is doped in the polysilicon layer, and a doped polysilicon layer is formed.

[0115] Comparative Example 4

[0116] The difference between Comparative Example 4 and Examples 1 and 2 is that a two-layer structure tunneling oxide layer is grown by combining high-temperature normal-pressure oxidation and low-temperature normal-pressure oxidation, and the specific process is as follows.

[0117] S1, an N-type silicon wafer with a resistivity of 10 Ω·cm and a thickness of 180 μm is prepared, the wafer is polished on both sides and cleaned, the wafer is placed in an LPCVD device, vacuumizing is performed, the temperature in the furnace tube is increased to 630°C, and oxygen with a flow rate of 10 L / min is passed in to normal pressure, the silicon wafer is oxidized for 12 minutes under high temperature and normal pressure, and a 0.8 nm thick loose oxide layer is continuously grown on the surface of the silicon wafer.

[0118] S2, continue to pass in oxygen, the pressure in the furnace tube is not changed, the temperature is decreased to 580°C, the silicon wafer is oxidized for 12 minutes under low temperature and normal pressure, and a 0.2 nm thick dense oxide layer is continuously grown on the surface of the silicon wafer; thus, a tunneling oxide layer structure with a dense inner side and a loose outer side is grown on the surface of the silicon wafer.

[0119] S3, continue to use the LPCVD device, the temperature in the furnace tube is controlled at 600°C, silane is passed in after vacuumizing, the vacuum pressure is 200 mTorr, and a polysilicon layer is deposited on the first oxide layer 2 under high temperature and low pressure.

[0120] S4, boron atom deposition and oxidation promotion are performed by using a high-temperature diffusion tube, boron trichloride and oxygen are passed in, deposition is performed at 830°C for 1000 seconds, the temperature is increased to 960°C, more oxygen is continuously passed in for 22 minutes, a certain concentration of boron is doped in the polysilicon layer, and a doped polysilicon layer is formed.

[0121] Comparative Example 5

[0122] Comparative Example 5 differs from Examples 1 and 2 in that two layers of the tunneling oxide layer are grown by combining low-temperature low-pressure oxidation and low-temperature normal-pressure oxidation, and the temperature for deposition and oxidation is different, as follows.

[0123] S1. A piece of N-type silicon wafer with a resistivity of 10 Ω-cm and a thickness of 180 μm is prepared, polished on both sides, cleaned, and placed in a LPCVD device. After vacuum pumping and waiting for the furnace tube to heat up to 570°C, oxygen is introduced at a flow rate of 10 L / min, and the pressure in the furnace tube is kept below 0.2 atm during the heating process. The silicon wafer is oxidized in a low-temperature low-pressure environment for 15 minutes, and a 0.8 nm-thick dense oxide layer is grown on the surface of the silicon wafer.

[0124] S2. Oxygen is continuously introduced, the pressure in the furnace tube is 1 atm, and the temperature in the furnace tube is 580°C. The silicon wafer is oxidized in a low-temperature normal-pressure environment for 12 minutes, and a 0.4 nm-thick relatively dense oxide layer is continuously grown on the surface of the silicon wafer. Thus, a two-layer dense tunneling oxide layer structure is grown on the surface of the silicon wafer.

[0125] S3. The LPCVD device is used to control the temperature in the furnace tube at 600°C, and after vacuum pumping, silane is introduced at a vacuum pressure of 200 mTorr. A polysilicon layer is deposited on the first oxide layer 2 in a high-temperature low-pressure environment.

[0126] S4. Boron atom deposition and oxidation are carried out using a high-temperature diffusion tube. Boron trichloride and oxygen are introduced, and the polysilicon layer is doped with a certain concentration of boron by depositing at 830°C for 1000 seconds and then increasing the temperature to 950°C and continuously introducing more oxygen for 22 minutes to form a doped polysilicon layer.

[0127] Comparative Example 6

[0128] Comparative Example 6 differs from Examples 1 and 2 in that two layers of the tunneling oxide layer are grown by combining low-temperature low-pressure oxidation and low-temperature normal-pressure oxidation, as follows.

[0129] S1. A piece of N-type silicon wafer with a resistivity of 10 Ω-cm and a thickness of 180 μm is prepared, polished on both sides, cleaned, and placed in a LPCVD device. After vacuum pumping and waiting for the furnace tube to heat up to 570°C, oxygen is introduced at a flow rate of 10 L / min, and the pressure in the furnace tube is kept below 0.2 atm during the heating process. The silicon wafer is oxidized in a low-temperature low-pressure environment for 15 minutes, and a 0.8 nm-thick dense oxide layer is grown on the surface of the silicon wafer.

[0130] S2, continue to pass in oxygen, the pressure in the furnace tube is 1 standard atmosphere, the temperature in the furnace tube is 580℃, the silicon wafer is oxidized in the low-temperature and normal-pressure environment for 12 minutes, and a 0.4nm-thick relatively dense oxide layer is continuously grown on the surface of the silicon wafer; thus, a two-layer dense tunneling oxide layer structure is grown on the surface of the silicon wafer.

[0131] S3, continue to use the LPCVD equipment, the temperature in the furnace tube is controlled at 600℃, silane is passed in after vacuumizing, the vacuum pressure is 200mTorr, and a polysilicon layer is deposited on the first oxide layer 2 in the high-temperature and low-pressure environment.

[0132] S4, deposition and oxidation promotion of boron atoms are performed by using a high-temperature diffusion tube, boron trichloride and oxygen are passed in, deposition is performed at 830℃ for 1000 seconds, the temperature is then increased to 960℃, more oxygen is continuously passed in for 22 minutes, a certain concentration of boron is doped in the polysilicon layer, and a doped polysilicon layer is formed.

[0133] Comparative Example 7

[0134] Comparative Example 7 and Examples 1 and 2 differ in that a two-layer structure of tunneling oxide layers is grown by combining low-temperature and low-pressure oxidation with low-temperature and normal-pressure oxidation, and the deposition and oxidation promotion temperatures are different, and the specific conditions are as follows.

[0135] S1, an N-type silicon wafer with a resistivity of 10Ω·cm and a thickness of 180μm is prepared, the wafer is polished on both sides and cleaned, is placed in the LPCVD equipment, is vacuumized, and after the temperature in the furnace tube is increased to 570℃, oxygen with a flow rate of 10L / min is passed in, the pressure in the furnace tube is kept below 0.2 standard atmosphere during the temperature increasing process, and the silicon wafer is oxidized in the low-temperature and low-pressure environment for 15 minutes, and a 0.8nm-thick dense oxide layer is grown on the surface of the silicon wafer.

[0136] S2, continue to pass in oxygen, the pressure in the furnace tube is 1 standard atmosphere, the temperature in the furnace tube is 580℃, the silicon wafer is oxidized in the low-temperature and normal-pressure environment for 12 minutes, and a 0.4nm-thick relatively dense oxide layer is continuously grown on the surface of the silicon wafer; thus, a two-layer dense tunneling oxide layer structure is grown on the surface of the silicon wafer.

[0137] S3, continue to use the LPCVD equipment, the temperature in the furnace tube is controlled at 600℃, silane is passed in after vacuumizing, the vacuum pressure is 200mTorr, and a polysilicon layer is deposited on the first oxide layer 2 in the high-temperature and low-pressure environment.

[0138] S4, deposition and oxidation promotion of boron atoms are performed by using a high-temperature diffusion tube, boron trichloride and oxygen are passed in, deposition is performed at 830℃ for 1000 seconds, the temperature is then increased to 970℃, more oxygen is continuously passed in for 22 minutes, a certain concentration of boron is doped in the polysilicon layer, and a doped polysilicon layer is formed.

[0139] Performance test

[0140] The silicon wafer with passivation contact structure obtained by the passivation method of the above examples and comparative examples was subjected to performance test. The data in Table 1 were directly tested using N-type silicon wafer with symmetric structure after double-sided growth of Poly layer and double-sided boron diffusion.

[0141] The minority carrier lifetime (Lifetime), recombination current density (J0), implied open circuit voltage (iVoc), and implied fill factor (iFF) were measured using WCT-120 instrument of Sinton Company, USA. The photoluminescence brightness was tested using PL-R3 instrument, wherein the excitation brightness was 1-fold solar standard brightness (1 Sun). The test results are shown in Table 1.

[0142] Table 1

[0143]

[0144] From the test results of Examples 1 and 2 and Comparative Example 1, it can be seen that the passivation method of the present application has obvious improvement in the minority carrier lifetime, iVoc, iFF and PL brightness, and obvious reduction in the recombination current density J0, compared with the boron-doped Poly layer prepared by the prior art, and shows good passivation effect.

[0145] From the test results of Examples 3 and 4 and Comparative Example 2, it can be seen that although the phosphorus Poly itself has good passivation performance, the passivation effect of the phosphorus-doped Poly layer prepared by the passivation method of the present application is still improved to some extent, compared with the prior art, and the minority carrier lifetime and PL brightness are obviously improved, the iVoc and iFF are improved, and the recombination current density J0 is reduced.

[0146] From the test results of Examples 1 and 2 and Comparative Examples 3 to 7, it can be seen that the passivation effect of the boron-doped and phosphorus-doped Poly layer structure can be greatly improved by the superposition of three layers of different dense oxide layers, compared with the two-layer structure, and the minority carrier lifetime, iVoc, iFF and PL brightness are obviously improved, and the recombination current density J0 is obviously reduced, showing good passivation effect. Moreover, the tunneling oxide layer grown by the present application is less affected by the temperature fluctuation of the subsequent boron diffusion, and can accept a fluctuation of 30℃ in the best oxidation promotion temperature.

[0147] From the test results of Examples 1, 2 and Comparative Examples 5-7, it can be seen that the tunnel oxide layer is passivated under different oxidation advancing temperatures for boron diffusion. If a low-temperature method is used throughout (Comparative Examples 5-7) to grow a dense tunnel oxide layer, a better passivation effect can usually be achieved at the optimum oxidation advancing temperature for boron diffusion (Comparative Example 6), but it is very sensitive to changes in the oxidation advancing temperature, and a temperature fluctuation of about 10°C (Comparative Example 5 and Comparative Example 7) will result in a significant decrease in the passivation effect, which is not conducive to large-scale industrial production.

[0148] The above further describes the present application with the aid of specific examples, but it should be understood that the specific description herein should not be construed as limiting the spirit and scope of the present application, and various modifications made to the above examples by those of ordinary skill in the art after reading the present specification are within the scope of the present application.

Claims

1. A passivated contact structure of boron, phosphorus doped Poly layer characterized in that, The passivation contact structure comprises a first oxide layer (2), a second oxide layer (3), a third oxide layer (4) and a doped polysilicon layer (5) grown on a silicon wafer (1), the doped polysilicon layer (5) is above the first oxide layer (2), the first oxide layer (2), the second oxide layer (2) and the third oxide layer (4) constitute a tunneling oxide layer, the second oxide layer (2) is located in the middle of the tunneling oxide layer and has a thickness of 0.5-1 nm and is loose, the first oxide layer (2) and the third oxide layer (4) are located on both sides of the tunneling oxide layer, the first oxide layer (2) has a thickness of 0.3-0.8 nm and is dense, and the third oxide layer (4) has a thickness of 0.1-0.4 nm and is dense.

2. The passivated contact structure of boron, phosphorus doped Poly layer as claimed in claim 1, wherein, The passivation contact structure is prepared by the following method: S1, providing a clean and polished silicon wafer, using an LPCVD device, vacuumizing, and continuously feeding oxygen at a temperature of 400-590 ℃ and a low pressure of 0.1-0.5 atm, to perform first oxidation on the silicon wafer, and to grow a first oxide layer (2) on the surface of the silicon wafer (1); S2, increasing the temperature by 50-220 ℃ based on the temperature in step S1, continuously feeding oxygen at a pressure greater than or equal to 1 atm, to perform second oxidation on the silicon wafer, and to grow a second oxide layer (3) on the surface of the silicon wafer (1); S3, stopping feeding oxygen, keeping the pressure unchanged, and reducing the temperature to below 600 ℃, to perform third oxidation on the silicon wafer, and to grow a third oxide layer (4) on the surface of the silicon wafer (1); S4, continuously using the LPCVD device, increasing the temperature by 0-50 ℃ based on the temperature in step S3, vacuumizing and then feeding silane, to deposit a polysilicon layer on the first oxide layer (2) at a high temperature and a low pressure, until the film thickness required by the process is reached; S5, using a high-temperature diffusion tube, to perform deposition and oxidation of boron atoms or phosphorus atoms, to dope a certain concentration of boron or phosphorus in the polysilicon layer, and to form a doped polysilicon layer (5).

3. The passivated contact structure of a boron, phosphorus doped Poly layer according to claim 1 or 2, characterized in that, The thickness of the three-layer oxide layer stack is equal to the thickness of a conventional tunneling oxide layer.

4. The passivated contact structure of boron, phosphorus doped Poly layer as claimed in claim 2, wherein, In step S1, the temperature is 500-580 ℃, and the first oxidation time is 10-20 minutes.

5. The passivated contact structure of boron, phosphorus doped Poly layer as claimed in claim 2, wherein, In step S2, the temperature is 610-640 ℃, the pressure is normal pressure, and the second oxidation time is 10-20 minutes.

6. The passivated contact structure of boron, phosphorus doped Poly layer as claimed in claim 2, wherein, In step S3, the temperature is 550-590 ℃, the pressure is normal pressure, and the third oxidation time is 10-20 minutes.

7. The passivated contact structure of boron, phosphorus doped Poly layer as claimed in claim 2, wherein, In steps S1 and S2, the flow rate of the fed oxygen is 5-30 L / min.

8. The passivated contact structure of boron, phosphorus doped Poly layer as claimed in claim 2, wherein, In step S4, the temperature is 550-640 ℃, and the vacuum pressure is 180-300 mTorr.

9. The passivated contact structure of boron, phosphorus doped Poly layer as claimed in claim 2, wherein, In step S5, in the process of deposition and oxidation of boron atoms, the deposition temperature is 800-850 ℃, and the oxidation temperature is 940-1000 ℃; in the process of deposition and oxidation of phosphorus atoms, the deposition temperature is 800-850 ℃, and the oxidation temperature is 880-920 ℃.

10. The passivated contact structure of boron, phosphorus doped Poly layer as claimed in claim 9, wherein, During the deposition and oxidation promotion process of boron atoms, boron trichloride and oxygen are introduced, first deposited at 800-850 DEG C for 600-1500 seconds, then heated to 940-1000 DEG C, and continue to introduce more oxygen to promote for more than 20 minutes; during the deposition and oxidation promotion process of phosphorus atoms, phosphorus oxychloride and oxygen are introduced, first deposited at 800-850 DEG C for 600-1500 seconds, then heated to 880-920 DEG C, and continue to introduce more oxygen to promote for 10-20 minutes.

11. The passivated contact structure of boron, phosphorus doped Poly layer as claimed in claim 1 or 2, wherein, The silicon wafer is an N-type silicon wafer.

12. A cell having a passivated contact structure with a boron, phosphorus doped Poly layer, characterized by, The battery comprises a silicon wafer and a passivation contact structure of a boron, phosphorus doped Poly layer formed on the surface of the silicon wafer as claimed in any one of claims 1-11.

13. The battery having a passivated contact structure with a boron, phosphorus doped Poly layer of claim 12, wherein, The battery is a TOPCon battery, a TBC battery or a perovskite laminated battery.

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