Chain push method for silicon wafer diffusion bonding

Abstract

The present invention discloses a chain-type advancement method for silicon wafer diffusion and bonding, wherein an odd-numbered batch heating section and an even-numbered batch heating section are arranged in a chain-type furnace; only when an odd-numbered batch of silicon wafers passes through the odd-numbered batch heating section, the heating device of the odd-numbered batch heating section is turned on to perform high-temperature advancement treatment on the odd-numbered batch of silicon wafers passing through; when no odd-numbered batch of silicon wafers passes through the odd-numbered batch heating section, the heating device of the odd-numbered batch heating section is turned off; only when an even-numbered batch of silicon wafers passes through the even-numbered batch heating section, the heating device of the even-numbered batch heating section is turned on to perform high-temperature advancement treatment on the even-numbered batch of silicon wafers passing through; when no even-numbered batch of silicon wafers passes through the even-numbered batch heating section, the heating device of the even-numbered batch heating section is turned off. The chain-type advancement method for silicon wafer diffusion and bonding of the present invention can perform high-temperature advancement treatment on silicon wafers that have completed BSG deposition, and can avoid the problem of excessive temperature caused by continuous heating of the furnace body and the internal atmosphere.

Description

Technical Field

[0001] The invention relates to a chain-type advancing method for silicon slice diffusion and bonding. Background Art

[0002] At present, the preparation of boron emitters in the photovoltaic industry is basically carried out by tubular thermal diffusion. Specifically, the silicon wafer is inserted into a quartz boat and then placed in a quartz tube, and the method of deposition first and then advancement is adopted. First, at a relatively low temperature, nitrogen carries BBr3 and O2 to react on the surface of the silicon wafer to form a borosilicate glass layer (BSG layer), and then the temperature is raised and high-temperature (greater than 950°C) advancement is carried out to obtain a boron emitter of a certain depth. Although this tubular deposition and advancement diffusion method can meet the requirements for the preparation of boron emitters, the high process temperature and long process time will lead to problems of excessive energy consumption and low production capacity.

[0003] Chain tunnel furnaces are increasingly used in the photovoltaic solar cell industry due to their rapid temperature rise and fall and more uniform heating characteristics. At present, they have been relatively maturely applied in the preparation process of monocrystalline silicon cells. In the front-end preparation process of solar cells, such as oxidation and phosphorus diffusion, attempts have been made to use chain tunnel furnace heating. Compared with chain phosphorus diffusion and oxidation processes, chain boron diffusion requires a higher process peak temperature (up to 1100°C) and a higher heating rate to achieve a short-term boron junction depth effect. Using infrared lamps to heat silicon wafers can achieve a higher heating rate, but to achieve a higher heating rate for silicon wafers, the output power of the lamps needs to be maintained at a relatively high level. If the lamps continue to output high power, the temperature of the tunnel furnace structure and the furnace atmosphere will inevitably reach above 1100°C, which places very high demands on the furnace and lamps, and is difficult to achieve in practice. Summary of the invention

[0004] In order to solve the defects of the prior art, the present invention provides a chain-type advancement method for silicon wafer diffusion junction, which uses a chain-type furnace to perform high-temperature advancement treatment on silicon wafers that have completed BSG deposition to form a boron diffusion junction;

[0005] The silicon wafers are sequentially conveyed in batches in the chain furnace, with each batch containing at least one silicon wafer; each batch of silicon wafers is sequentially counted along the conveying direction of the silicon wafers, and each batch of silicon wafers is divided into odd-numbered batches of silicon wafers and even-numbered batches of silicon wafers;

[0006] At least one high-temperature advancement processing zone is arranged in the chain furnace; two heating sections are arranged in the high-temperature advancement processing zone, and the two heating sections are arranged in sequence along the silicon wafer conveying direction, and heating devices are respectively arranged in the two heating sections; one of the heating sections is used as the odd-numbered batch heating section, and the other heating section is used as the even-numbered batch heating section;

[0007] The working mode of controlling the odd-numbered batch heating section is as follows: only when the odd-numbered batch of silicon wafers passes through the odd-numbered batch heating section, the heating device of the odd-numbered batch heating section is turned on, and the heating device performs high-temperature pushing treatment on the odd-numbered batch of silicon wafers passing through; when no odd-numbered batch of silicon wafers passes through the odd-numbered batch heating section, the heating device of the odd-numbered batch heating section is turned off, so that the temperature of the odd-numbered batch heating section is reduced;

[0008] The working mode of controlling the even-numbered batch heating section is as follows: only when an even-numbered batch of silicon wafers passes through the even-numbered batch heating section, the heating device of the even-numbered batch heating section is turned on, and the heating device performs high-temperature pushing treatment on the even-numbered batch of silicon wafers passing through the even-numbered batch heating section; when no even-numbered batch of silicon wafers passes through the even-numbered batch heating section, the heating device of the even-numbered batch heating section is turned off to reduce the temperature of the even-numbered batch heating section.

[0009] Preferably, two preheating sections are arranged in the high-temperature advancement treatment area, and the two preheating sections are arranged in sequence along the conveying direction of the silicon wafers, and heating devices are respectively arranged in the two preheating sections; one of the preheating sections is matched with the odd-numbered batch heating section, and the preheating section is the odd-numbered batch preheating section; the other preheating section is matched with the even-numbered batch heating section, and the preheating section is the even-numbered batch preheating section;

[0010] The working mode of controlling the odd-numbered batch preheating section is as follows: only when an odd-numbered batch of silicon wafers passes through the odd-numbered batch preheating section, the heating device of the odd-numbered batch preheating section is turned on, and the heating device preheats the odd-numbered batch of silicon wafers passing through; when no odd-numbered batch of silicon wafers passes through the odd-numbered batch preheating section, the heating device of the odd-numbered batch preheating section is turned off, so that the temperature of the odd-numbered batch preheating section is reduced;

[0011] The working mode of controlling the even-numbered batch preheating section is as follows: only when an even-numbered batch of silicon wafers passes through the even-numbered batch preheating section, the heating device of the even-numbered batch preheating section is turned on, and the heating device preheats the even-numbered batch of silicon wafers passing through the even-numbered batch preheating section; when no even-numbered batch of silicon wafers passes through the even-numbered batch preheating section, the heating device of the even-numbered batch preheating section is turned off to reduce the temperature of the even-numbered batch preheating section.

[0012] Preferably, the odd-numbered batch preheating section, the odd-numbered batch heating section, the even-numbered batch preheating section, and the even-numbered batch heating section in the high-temperature advancement treatment zone are sequentially arranged along the conveying direction of the silicon wafers;

[0013] Alternatively, the even-numbered batch preheating section, the even-numbered batch heating section, the odd-numbered batch preheating section, and the odd-numbered batch heating section in the high-temperature advancement processing zone are sequentially arranged along the silicon wafer conveying direction.

[0014] Preferably, the heating device is an infrared lamp.

[0015] Preferably, when the heating device of the odd-numbered batch heating section is turned on, nitrogen, oxygen or air is also introduced into the odd-numbered batch heating section;

[0016] When the heating device of the even-numbered batch heating section is turned on, nitrogen, oxygen or air is also introduced into the even-numbered batch heating section.

[0017] Preferably, the heating device of the odd-numbered batch preheating section is controlled to heat the odd-numbered batches of silicon wafers passing through to 100-200° C.;

[0018] The heating device of the even-numbered batch preheating section is controlled to heat the even-numbered batches of silicon wafers passing therethrough to 100-200°C.

[0019] Preferably, the time for odd-numbered batches of silicon wafers to pass through the odd-numbered batches of heating sections is controlled to be 15 to 20 seconds, the heating device of the odd-numbered batches of heating sections is controlled to heat the odd-numbered batches of silicon wafers to 1050 to 1120°C within 10 to 15 seconds, and the maximum temperature of the furnace atmosphere in the odd-numbered batches of heating sections is controlled to be 650 to 700 degrees.

[0020] Preferably, the time for the even-numbered batches of silicon wafers to pass through the even-numbered batches of heating section is controlled to be 15 to 20 seconds, the heating device of the even-numbered batches of heating section is controlled to heat the even-numbered batches of silicon wafers to 1050 to 1120°C within 10 to 15 seconds, and the maximum temperature of the furnace atmosphere in the even-numbered batches of heating section is controlled to be 650 to 700 degrees.

[0021] Preferably, a plurality of high-temperature driving-in processing zones are arranged in the chain furnace, and the plurality of high-temperature driving-in processing zones are arranged in sequence along the conveying direction of the silicon wafers.

[0022] Preferably, the total time for odd-numbered batches of silicon wafers to pass through the odd-numbered batches of heating sections of the above-mentioned multiple high-temperature advancement processing zones is controlled to be 150 to 240 seconds;

[0023] The total time for the even-numbered batches of silicon wafers to pass through the even-numbered batches of heating sections of the above-mentioned multiple high-temperature advancement processing zones is controlled to be 150 to 240 seconds.

[0024] The advantages and beneficial effects of the present invention are: providing a chain advancement method for silicon wafer diffusion bonding, which can perform high-temperature advancement treatment on silicon wafers that have completed BSG deposition, and can avoid the problem of excessive temperature caused by continuous heating of the furnace body and internal atmosphere.

[0025] The present invention has the following characteristics:

[0026] 1. The present invention uses infrared lamps to heat the transported silicon wafers. Since the silicon wafers can quickly absorb infrared rays and achieve rapid temperature rise to about 1100°C, a large number of vacancies and interstitial atoms will be generated near the surface of the silicon wafer during the rapid temperature rise of the silicon wafer. At high temperatures, these vacancies and interstitial atoms can promote the boron diffusion process, so that the rapid diffusion of boron can be achieved in a relatively short time. The single wafer is repeatedly advanced through 4 to 6 cycles, so that the silicon wafer can undergo multiple rapid temperature rise processes and use this principle multiple times to promote boron diffusion.

[0027] 2. The present invention controls the intermittent opening and closing of the heating devices (infrared lamps) in the odd-numbered batch heating section and the even-numbered batch heating section, thereby ensuring that the transmitted odd-numbered batches of silicon wafers and the even-numbered batches of silicon wafers can be irradiated and heated by the infrared lamps, and avoiding the problem of excessive temperature caused by the continuous heating of the furnace body and the internal atmosphere by the infrared lamps being continuously turned on. DETAILED DESCRIPTION

[0028] The specific implementation of the present invention is further described below in conjunction with the examples. The following examples are only used to more clearly illustrate the technical solutions of the present invention, and cannot be used to limit the protection scope of the present invention.

[0029] The present invention provides a method for preparing a boron emitter, comprising the following steps:

[0030] 1) Texturing: Place the silicon wafer in a KOH solution with a mass fraction of 0.5% to 2.0% to remove the original damage layer caused by the silicon wafer cutting process, and then place the silicon wafer in a mixed solution of KOH with a mass fraction of 0.5% to 2.5% and a texturing additive with a volume fraction of 0.5% to 1.5%. Texturing is performed on both sides of the silicon wafer, followed by post-processing and acid washing and drying.

[0031] 2) BSG deposition: insert the double-sided stack of silicon wafers after texturing into a quartz boat and place them in a furnace tube for BSG deposition; first, introduce O2 at 800-880°C for pre-oxidation of the silicon wafer for 500-1000s; then, at 840-900°C, use a small N2 to carry the BBr3 source to react with O2, with the ratio of the small N2 flow rate to the O2 flow rate in the range of 3-5:1, and the time is 1000-1800s; after deposition, the peak concentration of the silicon wafer is in the range of 1E20-3E20, and the boron junction depth is approximately in the range of 50-200nm.

[0032] 3) Chain advancement: A chain furnace is used to perform high-temperature advancement treatment on silicon wafers that have completed BSG deposition;

[0033] The silicon wafers are sequentially conveyed in batches in the chain furnace, with each batch containing at least one silicon wafer; each batch of silicon wafers is sequentially counted along the conveying direction of the silicon wafers, and each batch of silicon wafers is divided into odd-numbered batches of silicon wafers and even-numbered batches of silicon wafers;

[0034] A plurality of (specifically, 4 to 6) high-temperature advancement processing zones are arranged in the chain furnace, and the plurality of high-temperature advancement processing zones are arranged in sequence along the conveying direction of the silicon wafer;

[0035] Two heating sections and two preheating sections are arranged in each high-temperature advancement treatment zone: infrared lamp tubes (as heating devices) are arranged in the two heating sections and the two preheating sections respectively; one of the heating sections is used as the odd-numbered batch heating section, and the other heating section is used as the even-numbered batch heating section; one of the preheating sections is matched with the odd-numbered batch heating section, and the preheating section is used as the odd-numbered batch preheating section; the other preheating section is matched with the even-numbered batch heating section, and the preheating section is used as the even-numbered batch preheating section;

[0036] The odd-numbered batch preheating section, the odd-numbered batch heating section, the even-numbered batch preheating section, and the even-numbered batch heating section in each high-temperature advancement processing zone are sequentially arranged along the conveying direction of the silicon wafers;

[0037] Alternatively, the even-numbered batch preheating section, the even-numbered batch heating section, the odd-numbered batch preheating section, and the odd-numbered batch heating section in each high-temperature advancement processing zone are sequentially arranged along the conveying direction of the silicon wafers;

[0038] The working mode of controlling the odd-numbered batch preheating section is as follows: only when the odd-numbered batch of silicon wafers passes through the odd-numbered batch preheating section, the infrared lamp tube of the odd-numbered batch preheating section is turned on (the power output ratio of the lamp tube is controlled to be less than 20%), and the infrared lamp tube preheats the odd-numbered batch of silicon wafers passing through; when no odd-numbered batch of silicon wafers passes through the odd-numbered batch preheating section, the infrared lamp tube of the odd-numbered batch preheating section is turned off to reduce the temperature of the odd-numbered batch preheating section; specifically, the infrared lamp tube of the odd-numbered batch preheating section is controlled to heat the odd-numbered batch of silicon wafers passing through to 100-200° C.;

[0039] The working mode of controlling the odd-numbered batch heating section is as follows: only when the odd-numbered batch of silicon wafers passes through the odd-numbered batch heating section, the infrared lamp tube of the odd-numbered batch heating section is turned on (the power output ratio of the lamp tube is controlled to be above 80%), and the infrared lamp tube performs high-temperature advancement treatment on the odd-numbered batch of silicon wafers passing through; when no odd-numbered batch of silicon wafers passes through the odd-numbered batch heating section, the infrared lamp tube of the odd-numbered batch heating section is turned off to reduce the temperature of the odd-numbered batch heating section; and when the infrared lamp tube of the odd-numbered batch heating section is turned on, nitrogen, oxygen or air is also introduced into the odd-numbered batch heating section; specifically, the time for the odd-numbered batch of silicon wafers to pass through the odd-numbered batch heating section is controlled to be 15 to 20 seconds, and the infrared lamp tube of the odd-numbered batch heating section is controlled to heat the odd-numbered batch of silicon wafers passing through to 1050 to 1120° C. within 10 to 15 seconds. Since the infrared lamp tube of the odd-numbered batch heating section is turned on for a short time, the maximum temperature of the furnace atmosphere of the odd-numbered batch heating section will be controlled to be 650 to 700 degrees;

[0040] The working mode of controlling the even-numbered batch preheating section is as follows: only when the even-numbered batch of silicon wafers passes through the even-numbered batch preheating section, the infrared lamp tube of the even-numbered batch preheating section is turned on (the power output ratio of the lamp tube is controlled to be less than 20%), and the infrared lamp tube preheats the even-numbered batch of silicon wafers passing through; when no even-numbered batch of silicon wafers passes through the even-numbered batch preheating section, the infrared lamp tube of the even-numbered batch preheating section is turned off to reduce the temperature of the even-numbered batch preheating section; specifically, the infrared lamp tube of the even-numbered batch preheating section is controlled to heat the even-numbered batch of silicon wafers passing through to 100-200°C;

[0041] The working mode of controlling the even-numbered batch heating section is as follows: only when the even-numbered batch of silicon wafers passes through the even-numbered batch heating section, the infrared lamp tube of the even-numbered batch heating section is turned on (the power output ratio of the lamp tube is controlled to be above 80%), and the infrared lamp tube performs high-temperature advancement treatment on the even-numbered batch of silicon wafers passing through; when no even-numbered batch of silicon wafers passes through the even-numbered batch heating section, the infrared lamp tube of the even-numbered batch heating section is turned off to reduce the temperature of the even-numbered batch heating section; and when the infrared lamp tube of the even-numbered batch heating section is turned on, nitrogen, oxygen or air is also introduced into the even-numbered batch heating section; specifically, the time for the even-numbered batch of silicon wafers to pass through the even-numbered batch heating section is controlled to be 15 to 20 seconds, and the infrared lamp tube of the even-numbered batch heating section is controlled to heat the even-numbered batch of silicon wafers passing through to 1050 to 1120° C. within 10 to 15 seconds. Since the infrared lamp tube of the even-numbered batch heating section is turned on for a short time, the maximum temperature of the furnace atmosphere of the even-numbered batch heating section will be controlled to be 650 to 700 degrees;

[0042] The total time for odd-numbered batches of silicon wafers to pass through the odd-numbered batches of heating sections of the above-mentioned multiple high-temperature push-in processing zones is controlled to be 150 to 240 seconds;

[0043] The total time for the even-numbered batches of silicon wafers to pass through the even-numbered batches of heating sections of the above-mentioned multiple high-temperature advancement processing zones is controlled to be 150 to 240 seconds;

[0044] Both odd-numbered batches of silicon wafers and even-numbered batches of silicon wafers can form boron diffused junctions, and the boron junctions are uniform, with a boron surface concentration of 1e19atoms / cm3 to 1e20atom / cm3 and a junction depth of about 0.7-1.0um.

[0045] The present invention adopts infrared lamp tubes to heat silicon wafers conveyed in a chain furnace. Since the silicon wafers can quickly absorb infrared rays and realize rapid heating to about 1100°C, a large number of vacancies and interstitial atoms will be generated near the surface of the silicon wafers during the rapid heating process of the silicon wafers. At high temperatures, these vacancies and interstitial atoms can promote the boron diffusion process, so that the rapid diffusion of boron can be realized in a relatively short time. The single wafer is repeatedly advanced through 4 to 6 cycles, so that the silicon wafer can undergo multiple rapid heating processes and utilize this principle multiple times to promote the diffusion of boron.

[0046] The present invention controls the intermittent opening and closing of the infrared lamps in the odd-numbered batch heating section and the even-numbered batch heating section in the chain furnace, thereby ensuring that the transmitted odd-numbered batches of silicon wafers and the even-numbered batches of silicon wafers can be irradiated and heated by the infrared lamps, and avoiding the problem of excessive temperature caused by the continuous heating of the furnace body and the internal atmosphere by the infrared lamps being continuously turned on.

[0047] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. The chain-type advancement method for silicon wafer diffusion junction uses a chain furnace to perform high-temperature advancement treatment on silicon wafers that have completed BSG deposition to form a boron diffusion junction; it is characterized by: The silicon wafers are sequentially conveyed in batches in the chain furnace, with each batch containing at least one silicon wafer; each batch of silicon wafers is sequentially counted along the conveying direction of the silicon wafers, and each batch of silicon wafers is divided into odd-numbered batches of silicon wafers and even-numbered batches of silicon wafers; At least one high-temperature advancement processing zone is arranged in the chain furnace; two heating sections are arranged in the high-temperature advancement processing zone, and the two heating sections are arranged in sequence along the silicon wafer conveying direction, and heating devices are respectively arranged in the two heating sections; one of the heating sections is used as the odd-numbered batch heating section, and the other heating section is used as the even-numbered batch heating section; The working mode of controlling the odd-numbered batch heating section is as follows: only when the odd-numbered batch of silicon wafers passes through the odd-numbered batch heating section, the heating device of the odd-numbered batch heating section is turned on, and the heating device performs high-temperature pushing treatment on the odd-numbered batch of silicon wafers passing through; when no odd-numbered batch of silicon wafers passes through the odd-numbered batch heating section, the heating device of the odd-numbered batch heating section is turned off, so that the temperature of the odd-numbered batch heating section is reduced; The working mode of controlling the even-numbered batch heating section is as follows: only when an even-numbered batch of silicon wafers passes through the even-numbered batch heating section, the heating device of the even-numbered batch heating section is turned on, and the heating device performs high-temperature pushing treatment on the even-numbered batch of silicon wafers passing through the even-numbered batch heating section; when no even-numbered batch of silicon wafers passes through the even-numbered batch heating section, the heating device of the even-numbered batch heating section is turned off to reduce the temperature of the even-numbered batch heating section.

2. The chain-type advancing method for silicon wafer diffusion bonding according to claim 1, characterized in that: Two preheating sections are arranged in the high-temperature advancement treatment area, and the two preheating sections are arranged in sequence along the direction of silicon wafer conveying, and heating devices are respectively arranged in the two preheating sections; one of the preheating sections is matched with the odd-numbered batch heating section, and the preheating section is the odd-numbered batch preheating section; the other preheating section is matched with the even-numbered batch heating section, and the preheating section is the even-numbered batch preheating section; The working mode of controlling the odd-numbered batch preheating section is as follows: only when an odd-numbered batch of silicon wafers passes through the odd-numbered batch preheating section, the heating device of the odd-numbered batch preheating section is turned on, and the heating device preheats the odd-numbered batch of silicon wafers passing through; when no odd-numbered batch of silicon wafers passes through the odd-numbered batch preheating section, the heating device of the odd-numbered batch preheating section is turned off, so that the temperature of the odd-numbered batch preheating section is reduced; The working mode of controlling the even-numbered batch preheating section is as follows: only when an even-numbered batch of silicon wafers passes through the even-numbered batch preheating section, the heating device of the even-numbered batch preheating section is turned on, and the heating device preheats the even-numbered batch of silicon wafers passing through the even-numbered batch preheating section; when no even-numbered batch of silicon wafers passes through the even-numbered batch preheating section, the heating device of the even-numbered batch preheating section is turned off to reduce the temperature of the even-numbered batch preheating section.

3. The chain-type advancing method for silicon wafer diffusion bonding according to claim 2, characterized in that: The odd-numbered batch preheating section, odd-numbered batch heating section, even-numbered batch preheating section, and even-numbered batch heating section in the high-temperature advancement processing zone are arranged in sequence along the conveying direction of the silicon wafers; Alternatively, the even-numbered batch preheating section, the even-numbered batch heating section, the odd-numbered batch preheating section, and the odd-numbered batch heating section in the high-temperature advancement processing zone are sequentially arranged along the silicon wafer conveying direction.

4. The chain-type advancing method for silicon wafer diffusion bonding according to claim 2, characterized in that: The heating device is an infrared lamp.

5. The chain-type advancing method for silicon wafer diffusion bonding according to claim 1, characterized in that: When the heating device of the odd-numbered batch heating section is turned on, nitrogen, oxygen or air is also introduced into the odd-numbered batch heating section; When the heating device of the even-numbered batch heating section is turned on, nitrogen, oxygen or air is also introduced into the even-numbered batch heating section.

6. The chain-type advancing method for silicon wafer diffusion bonding according to claim 3, characterized in that: Controlling the heating device of the odd-numbered batch preheating section to heat the odd-numbered batches of silicon wafers passing through to 100-200° C.; The heating device of the even-numbered batch preheating section is controlled to heat the even-numbered batches of silicon wafers passing therethrough to 100-200°C.

7. The chain-type advancing method for silicon wafer diffusion bonding according to claim 1, characterized in that: The time for odd-numbered batches of silicon wafers to pass through the odd-numbered batches of heating section is controlled to be 15 to 20 seconds, and the heating device of the odd-numbered batches of heating section is controlled to heat the odd-numbered batches of silicon wafers to 1050 to 1120°C within 10 to 15 seconds, and the maximum temperature of the furnace atmosphere in the odd-numbered batches of heating section is controlled to be 650 to 700 degrees.

8. The chain-type advancing method for silicon wafer diffusion bonding according to claim 1, characterized in that: The time for the even-numbered batches of silicon wafers to pass through the even-numbered batches of heating section is controlled to be 15 to 20 seconds, and the heating device of the even-numbered batches of heating section is controlled to heat the even-numbered batches of silicon wafers to 1050 to 1120°C within 10 to 15 seconds, and the maximum temperature of the furnace atmosphere in the even-numbered batches of heating section is controlled to be 650 to 700 degrees.

9. The chain-type advancing method for silicon wafer diffusion bonding according to claim 1, characterized in that: A plurality of high-temperature driving processing zones are arranged in the chain furnace, and the plurality of high-temperature driving processing zones are arranged in sequence along the conveying direction of the silicon wafers.

10. The chain-type advancing method for silicon wafer diffusion bonding according to claim 9, characterized in that: The total time for odd-numbered batches of silicon wafers to pass through the odd-numbered batches of heating sections of the above-mentioned multiple high-temperature push-in processing zones is controlled to be 150 to 240 seconds; The total time for the even-numbered batches of silicon wafers to pass through the even-numbered batches of heating sections of the above-mentioned multiple high-temperature advancement processing zones is controlled to be 150 to 240 seconds.