Manufacturing methods for single-crystal silicon rods, silicon wafers and their manufacturing methods, and single-crystal furnaces.

Abstract

This disclosure provides a method for manufacturing a single-crystal silicon rod, a silicon wafer, the same method for manufacturing the wafer, and a single-crystal furnace. The manufacturing method includes: drawing a single-crystal silicon rod using the Czochralski method in a single-crystal furnace; subjecting the single-crystal silicon rod to a first heat treatment in the single-crystal furnace, wherein the temperature range of the first heat treatment is 650°C to 800°C and the duration ranges from 5 minutes to 90 minutes; and subjecting the single-crystal silicon rod after the first heat treatment to a second heat treatment in the single-crystal furnace, wherein the temperature range of the second heat treatment is 100°C to 300°C and the duration ranges from 10 minutes to 60 minutes, wherein the resistivity of the single-crystal silicon rod after the second heat treatment is greater than 1000 Ω·cm and the conductivity type is P-type.

Claims

1. A method for manufacturing a single-crystal silicon rod, the method comprising: In a single crystal furnace, a single crystal silicon rod is drawn using the Czochralski method. In the single crystal furnace, the single crystal silicon rod undergoes a first heat treatment at a temperature ranging from 650°C to 800°C for a duration ranging from 5 minutes to 90 minutes. In the single crystal furnace, the single crystal silicon rod after the first heat treatment undergoes a second heat treatment at a temperature ranging from 100°C to 300°C for a duration ranging from 10 minutes to 60 minutes. The resistivity of the single crystal silicon rod after the second heat treatment is greater than 1000 Ω·cm, and its conductivity is P-type.

2. The method for manufacturing a single-crystal silicon rod as described in claim 1, wherein, After the first heat treatment is completed and before the second heat treatment begins, the manufacturing method further includes: cooling the single-crystal silicon rod from the temperature of the first heat treatment to the temperature of the second heat treatment using a cooling medium, the cooling medium including liquid nitrogen or liquid argon.

3. A method for manufacturing a single-crystal silicon rod as described in claim 1 or 2, wherein, After the first heat treatment is completed and before the second heat treatment begins, the manufacturing method further includes a cooling process of cooling the single crystal silicon rod from the temperature of the first heat treatment to the temperature of the second heat treatment at a cooling rate of not less than 15°C / min.

4. A method for manufacturing a single-crystal silicon rod as described in claim 1 or 2, wherein, The single crystal furnace includes a main furnace chamber and an auxiliary furnace chamber. A temperature control device is provided in the auxiliary furnace chamber, wherein the temperature control device is used to adjust the temperature in the auxiliary furnace chamber to perform the first heat treatment and the second heat treatment on the single crystal silicon rod in the auxiliary furnace chamber.

5. A method for manufacturing a single-crystal silicon rod as described in claim 1 or 2, wherein, The oxygen content of the single-crystal silicon rod after the second heat treatment is less than 8 ppma.

6. A method for manufacturing a silicon wafer, the method comprising: A single-crystal silicon rod made by any of the methods described in claims 1 to 5 is cut, ground, polished, and cleaned to obtain a silicon wafer.

7. A silicon wafer manufactured using the silicon wafer manufacturing method according to claim 6, wherein, The silicon wafer has a resistivity greater than 1000 Ω·cm, a P-type conductivity, and an oxygen content of less than 8 ppma.

8. A single crystal furnace for performing a method of manufacturing a single crystal silicon rod as described in any one of claims 1 to 5.

9. The single crystal furnace as described in claim 8, wherein, The single crystal furnace includes a main furnace chamber, an auxiliary furnace chamber, and a temperature control device disposed in the auxiliary furnace chamber. The temperature control device includes a heater, wherein the heater is used to perform a first heat treatment and a second heat treatment on the single crystal silicon rod. The temperature range of the first heat treatment is 650°C to 800°C, and the temperature range of the second heat treatment is 100°C to 300°C.

10. The single crystal furnace as described in claim 9, wherein, The temperature control device further includes a supply device for supplying a cooling medium, wherein the supply device is used to cool the single crystal silicon rod from the temperature of the first heat treatment to the temperature of the second heat treatment at a cooling rate of not less than 15°C / min by supplying a cooling medium to the auxiliary furnace chamber after the first heat treatment is completed and before the second heat treatment begins.

Images