Method for growing single crystal
According to an embodiment of the present invention, there is provided a method for growing a single crystal ingot having a target resistivity in a silicon melt by the Czochralski method, including steps of: deriving a resistivity value according to a dopant concentration included in a raw material and tabulating the resistivity value with reliable data; setting a reference value of a dopant concentration with respect to a target resistivity value; deriving a measurement value with respect to the dopant concentration included in the raw material itself; calculating a difference value between the reference value and the measurement value; and performing a counter doping on the silicon melt as much as the difference value. Accordingly, a single crystal ingot having a resistivity of 8 kΩ or more can be grown without improving impurities included in the raw material itself.
1. A method for growing a single crystal ingot having a target resistivity in a silicon melt by the Czochralski method, comprising:
deriving a resistivity value according to a dopant concentration included in a raw material to tabulate the derived resistivity value with reliable data;
setting a reference value of a dopant concentration with respect to a target resistivity value;
deriving a measurement value with respect to the dopant concentration included in the raw material itself;
calculating a difference value between the reference value and the measurement value; and
performing a counter doping on the silicon melt as much as the difference value.
2. The method of claim 1 , wherein the target resistivity is in a range of 8 to 14 kΩcm.
3. The method of claim 1 , wherein the single crystal ingot is a P-type.
4. The method of claim 1 , wherein the dopant concentration is a value obtained by subtracting an N-type dopant concentration from a P-type dopant concentration.
5. The method claim 4 , wherein the P-type dopant is boron and the N-type dopant is phosphorus.
6. The method claim 1 , wherein the deriving of the measurement value with respect to the dopant concentration included in the raw material itself comprises measuring a dopant concentration by introducing only a polysilicon into the silicon melt without introducing a dopant to grow an ingot.
7. The method claim 1 , wherein the raw material comprises a polysilicon and a quartz crucible.
8. The method claim 1 , wherein the performing of the counter doping on the silicon melt as much as the difference value comprises introducing an N-type dopant into the silicon melt as much as the difference value.
9. The method claim 1 , wherein the reference value is a theoretical value capable of obtaining a resistivity in a range of 8 to 14 KΩ cm in entire body sections of the single crystal ingot.
10. The method claim 1 , wherein an N-type dopant necessary at 0 cm of the single crystal ingot body is 29.6% with respect to an actual counter doping amount due to a segregation coefficient of a dopant, and the counter doping amount is calculated by the following Equation 1,
C
=
(
A
-
B
)
×
1
k
[
Equation
1
]
{A: impurity measurement value of a raw material (P-type impurity concentration−N-type impurity concentration), B: P-type impurity concentration for obtaining target resistivity−reference value of N-type impurity, C: counter doping amount and concentration of N-type impurity, and K: correction value according to segregation of N-type impurity (0.296)}.