Monocrystalline silicon argon annealing sheet preparation method for eliminating stress at positioning notch position

Abstract

The invention relates to a monocrystalline silicon argon annealing sheet preparation method capable of eliminating stress at a positioning notch position, which belongs to the technical field of silicon wafer processing, and comprises the following operation steps of: 1, putting monocrystalline silicon into a heat treatment furnace, setting the heating temperature to be 800 DEG C, and keeping for 2 hours; and 2, in the argon annealing process, the flow of argon is set to be 1.5 L / min, and the holding time is 3 hours. And thirdly, in the annealing process, the annealing temperature is set to be 900 DEG C, and the holding time is 4 hours. And 4, in the whole annealing process, monitoring and adjusting the annealing process in real time by adopting a whole-process monitoring and feedback system. And the supporting point stress on the surface of the monocrystalline silicon is effectively eliminated, so that defects of local metal, slip lines and the like are avoided. And the effect of eliminating the stress at the positioning notch position by the argon annealing technology is improved, so that an annealed sheet which is free of defects and low in bulk metal is obtained. And the temperature performance and reliability of argon annealing are improved.

Description

Technical Field

[0001] The invention relates to the technical field of silicon wafer processing, and in particular to a method for preparing a single crystal silicon argon annealing wafer for eliminating stress at a positioning cut position. Background Art

[0002] In the field of semiconductor material preparation technology, single crystal silicon is an important basic material. It has good electrical properties and thermal stability and is widely used in the manufacture of various electronic devices. However, single crystal silicon is often affected by various factors during the preparation process, such as temperature, pressure, impurities, etc., which will cause stress inside the single crystal silicon, thereby affecting its performance. Argon annealing is a commonly used method to eliminate the internal stress of single crystal silicon. It anneals the single crystal silicon using argon at high temperature to achieve the purpose of eliminating stress.

[0003] In the existing technology, argon annealing is a common method to eliminate the internal stress of single crystal silicon. This method mainly uses argon gas to anneal the single crystal silicon at high temperature to achieve the purpose of eliminating stress. However, although this method can effectively eliminate the stress inside the single crystal silicon, in actual operation, due to the uncertainty of factors such as temperature control and gas flow control during the annealing process, it may cause support point stress on the surface of the single crystal silicon after annealing, thereby causing local metal, slip line and other defects.

[0004] Although the existing argon annealing technology can effectively eliminate the stress inside the single crystal silicon, in actual operation, due to the uncertainty of factors such as temperature control and gas flow control during the annealing process, support point stress may appear on the surface of the single crystal silicon after annealing, resulting in the production of local metal, slip lines, etc. In addition, this method is not effective in eliminating the stress at the positioning cut position, and often cannot obtain defect-free and low-bulk metal annealed sheets. These problems and shortcomings limit the application scope and effect of the existing argon annealing technology, and also affect the performance and quality of single crystal silicon materials. Summary of the invention

[0005] The present invention mainly solves the deficiencies in the prior art and provides a method for preparing a single crystal silicon argon annealed sheet that eliminates the stress at the positioning cut position, which effectively eliminates the support point stress on the surface of the single crystal silicon to avoid the generation of local metal, slip lines and the like. The effect of argon annealing technology on eliminating the stress at the positioning cut position is improved to obtain an annealed sheet without defects and with low body metal. The parameters such as temperature control and gas flow control during the annealing process are optimized to improve the temperature performance and reliability of argon annealing.

[0006] The above technical problems of the present invention are mainly solved by the following technical solutions: A method for preparing a single crystal silicon argon annealed wafer for eliminating stress at a positioning cut position, comprising the following steps: Step 1: Place the single crystal silicon in a heat treatment furnace, set the heating temperature to 800°C, and hold it for 2 hours. By precisely controlling the heating temperature and time, the stress at the supporting points on the surface of the single crystal silicon is effectively eliminated.

[0007] Step 2: During the argon annealing process, the argon flow rate is set to 1.5L / min and maintained for 3 hours. By precisely controlling the argon flow rate, the stress at the location of the positioning cut is effectively eliminated. When the furnace tube is preheated without load, the gas flow rate has been set to 1.5L / min. The flow rate is controlled by high-precision MFC, and the overall fluctuation is maintained at 2%, ensuring that the gas flow rate remains constant throughout the process, avoiding heat conduction losses and fluctuations caused by gas fluctuations; Step 3: During the annealing process, the annealing temperature is set to 900°C and the holding time is 4 hours. By precisely controlling the temperature during the annealing process, the annealing process is made more stable and reliable.

[0008] Step 4: During the entire annealing process, a full-process monitoring and feedback system is used to monitor and adjust the annealing process in real time. By accurately controlling the temperature of the annealing process, the annealing process is made more stable and reliable. This real-time monitoring PID real-time temperature adjustment mode performs trickle temperature compensation correction and real-time feedback, and controls the proportion, integral and differential of the error generated by comparing the information collected by the real-time data of the controlled object with the given value. This control system is referred to as the PID control system-Proportional Integral Derivative.

[0009] Preferably, when argon ions are injected into single crystal silicon, the high-energy incident ions will collide with the atoms on the single crystal silicon lattice, causing some lattice atoms to shift, resulting in a large number of vacancies, which will cause the atomic arrangement in the injected area to become chaotic or turn it into an amorphous area. After the ion injection, the single crystal silicon must be annealed at a certain temperature to restore the crystal structure and eliminate defects.

[0010] Preferably, during the heat treatment of single crystal silicon, the temperature rise rate is 8°C to 12°C per minute to 800°C; during the annealing process, the temperature rise rate is 3°C to 7°C per minute from 800°C to 900°C.

[0011] Preferably, the implementation monitoring and feedback system is as follows: Step 1: Input temperature setting value and control parameter, and output temperature measurement value and temperature control status.

[0012] Step 2: To obtain the temperature measurement value, the TC-thermocouple is input into the temperature controller.

[0013] Step 3: Control the heater temperature by internal control calculation and then output the heater temperature control signal to the outside.

[0014] Step 4: The control signal of the internal heater is converted into a gate pulse signal, and the gate pulse is output to the controllable silicon power supply, and power is supplied to the heater. Usually, repeating the first to fourth steps is called feedback control.

[0015] Preferably, a three-step method of stepwise heating and cooling and long-term heat preservation is adopted to achieve gradual relaxation and release of internal stress of the silicon wafer. The first step: heating temperature is 800°C, holding time is 2 hours, gas flow rate is 1.5L / min; the second step: heating from 800°C to 900°C at a heating rate of 5°C / min, and keeping warm for 3 hours; the third step: cooling from 900°C to 650°C at a cooling rate of 5°C / min, and keeping at this temperature for half an hour to relax stress.

[0016] The present invention can achieve the following effects: The present invention provides a method for preparing a single crystal silicon argon annealed wafer for eliminating the stress at the location of the positioning cut. Compared with the prior art, the method effectively eliminates the stress at the supporting points on the surface of the single crystal silicon to avoid the generation of local metal, slip lines and the like. The effect of the argon annealing technology on eliminating the stress at the location of the positioning cut is improved to obtain an annealed wafer without defects and with low body metal. The technical problem of optimizing the temperature control, gas flow control and other parameters during the annealing process to improve the temperature resistance and reliability of the argon annealing is solved. The stress at the supporting points on the surface of the single crystal silicon is effectively eliminated, and the effect of the argon annealing technology on eliminating the stress at the location of the positioning cut is improved, thereby obtaining an annealed wafer without defects and with low body metal. DETAILED DESCRIPTION

[0017] The technical solution of the invention is further specifically described below through embodiments.

[0018] Embodiment: A method for preparing a single crystal silicon argon annealed wafer for eliminating stress at a positioning cut position, comprising the following steps: Step 1: Place the single crystal silicon in a heat treatment furnace, set the heating temperature to 800°C, and hold it for 2 hours. During the heat treatment of the single crystal silicon, the temperature rises by 8°C to 12°C per minute to 800°C.

[0019] Step 2: During the argon annealing process, the argon flow rate is set to 1.5L / min and maintained for 3 hours. When the furnace tube is preheated without load, the gas flow rate has been set to 1.5L / min. The flow rate is controlled by high-precision MFC, and the overall fluctuation is maintained at 2%, ensuring that the gas flow rate remains constant throughout the process and avoiding heat conduction losses and fluctuations caused by gas fluctuations.

[0020] When argon ions are injected into single crystal silicon, the high-energy incident ions will collide with the atoms on the single crystal silicon lattice, causing some lattice atoms to shift, resulting in a large number of vacancies, which will cause the atoms in the injected area to be arranged in disorder or become an amorphous area. After the ion implantation, the single crystal silicon must be annealed at a certain temperature to restore the crystal structure and eliminate defects.

[0021] Step 3: During the annealing process, the annealing temperature is set to 900°C and the holding time is 4 hours. The temperature rise rate is 3°C to 7°C per minute from 800°C to 900°C.

[0022] A three-step method of step-by-step heating and cooling and long-term insulation is used to achieve gradual relaxation and release of internal stress in the silicon wafer. The first step: heating temperature is 800°C, holding time is 2 hours, gas flow rate is 1.5L / min; the second step: heating from 800°C to 900°C at a heating rate of 5°C / min, and keeping warm for 3 hours; the third step: cooling from 900°C to 650°C at a cooling rate of 5°C / min, and keeping at this temperature for half an hour to relax stress.

[0023] Step 4: During the entire annealing process, a full-process monitoring and feedback system is used to monitor and adjust the annealing process in real time.

[0024] It can effectively eliminate the internal stress of single crystal silicon, so it can not only be used in the annealing treatment of ordinary single crystal silicon, but also in special occasions that require high-quality single crystal silicon materials, such as the manufacture of high-end electronic devices, etc., which expands the application scope of argon annealing technology.

[0025] This real-time monitoring PID real-time temperature adjustment mode performs trickle temperature compensation correction and real-time feedback. It controls the control system by comparing the information collected by the real-time data of the controlled object with the given value and the proportion, integration and differentiation of the error generated. It is referred to as PID control system - Proportional Integral Derivative.

[0026] The implementation of the monitoring and feedback system is as follows: Step 1: Input temperature setting value and control parameter, output temperature measurement value and temperature control status; Step 2: To obtain the temperature measurement value, the TC-thermocouple is input into the temperature controller; Step 3: Control the heater temperature, perform internal control calculations, and then output the heater control signal to the outside; Step 4: The control signal of the internal heater is converted into a gate pulse signal, and the gate pulse is output to the controllable silicon power supply, and power is supplied to the heater. Usually, repeating the first to fourth steps is called feedback control.

[0027] In summary, the method for preparing a single crystal silicon argon annealed sheet that eliminates the stress at the positioning cut position effectively eliminates the stress at the supporting points on the surface of the single crystal silicon to avoid the generation of local metal, slip lines and other defects, thereby improving the performance and quality of the single crystal silicon material. The effect of argon annealing technology on eliminating the stress at the positioning cut position is improved to obtain an annealed sheet without defects and with low body metal. The parameters such as temperature control and gas flow control during the annealing process are optimized to improve the temperature performance and reliability of argon annealing.

[0028] The above description is only a specific embodiment of the present invention, but the structural features of the present invention are not limited thereto. Any changes or modifications made by any technician in the field of the present invention are included in the patent scope of the present invention.

Claims

1. A method for preparing a single crystal silicon argon annealed wafer to eliminate stress at a positioning cut, characterized in that The steps are as follows: Step 1: Place the single crystal silicon into a heat treatment furnace, set the heating temperature to 800°C, and hold it for 2 hours; Step 2: During the argon annealing process, the argon flow rate was set to 1.5L / min and maintained for 3 hours. When the furnace tube was preheated without load, the gas flow rate was set to 1.5L / min. The flow rate was controlled by high-precision MFC, and the overall fluctuation was kept at 2%, ensuring that the gas flow rate remained constant throughout the process and avoiding heat conduction losses and fluctuations caused by gas fluctuations. Step 3: During the annealing process, the annealing temperature was set to 900°C and the holding time was 4 hours; Step 4: During the entire annealing process, a full-process monitoring and feedback system is used to monitor and adjust the annealing process in real time; This real-time monitoring PID real-time temperature adjustment mode performs trickle temperature compensation correction and real-time feedback. It controls the control system by comparing the information collected by the real-time data of the controlled object with the given value and the proportion, integration and differentiation of the error generated. It is referred to as PID control system - Proportional Integral Derivative.

2. The method for preparing a single crystal silicon argon annealed wafer for eliminating stress at a positioning cutout according to claim 1, characterized in that: When argon ions are injected into single crystal silicon, the high-energy incident ions will collide with the atoms on the single crystal silicon lattice, causing some lattice atoms to shift, resulting in a large number of vacancies, which will cause the atoms in the injected area to be arranged in disorder or become an amorphous area. After the ion implantation, the single crystal silicon must be annealed at a certain temperature to restore the crystal structure and eliminate defects.

3. The method for preparing a single crystal silicon argon annealed wafer for eliminating stress at a positioning cutout according to claim 1, characterized in that: During the heat treatment of single crystal silicon, the temperature rise rate is 8℃~12℃ per minute to 800℃; during the annealing process, the temperature rise rate is 3℃~7℃ per minute from 800℃ to 900℃.

4. The method for preparing a single crystal silicon argon annealed wafer for eliminating stress at a positioning cutout according to claim 1, characterized in that The implementation monitoring and feedback system is as follows: Step 1: Input temperature setting value and control parameter, output temperature measurement value and temperature control status; Step 2: To obtain the temperature measurement value, the TC-thermocouple is input into the temperature controller; Step 3: Control the heater temperature, perform internal control calculations, and then output the heater control signal to the outside; Step 4: The control signal of the internal heater is converted into a gate pulse signal, and the gate pulse is output to the controllable silicon power supply, and power is supplied to the heater. Usually, repeating the first to fourth steps is called feedback control.

5. The method for preparing a single crystal silicon argon annealed wafer for eliminating stress at a positioning cutout according to claim 1, characterized in that: The three-step method of step-by-step heating and cooling and long-term heat preservation is used to gradually relax and release the internal stress of the silicon wafer. The first step: heating temperature is 800℃, holding time is 2 hours, gas flow rate is 1.5L / min; the second step: heating from 800℃ to 900℃ at a heating rate of 5℃ / min, and keeping warm for 3 hours; Step 3: Cool down from 900°C to 650°C at a cooling rate of 5°C / min and keep at this temperature for half an hour to relax the stress.