Method for forming impurity-introduced layer, method for cleaning object to be processed apparatus for introducing impurity and method for producing device
View Patent ↗A method of forming an impurity-introduced layer is disclosed. The method includes at least a step of forming a resist pattern on a principal face of a solid substrate such as a silicon substrate (S 27 ); a step of introducing impurity into the solid substrate through plasma-doping in ion mode (S 23 ), a step of removing a resist (S 28 ), a step of cleaning metal contamination and particles attached to a surface of the solid substrate (S 25 a ); a step of anneal (S 26 ). The step of removing a resist (S 28 ) irradiates the resist with oxygen-plasma or brings mixed solution of sulfuric acid and hydrogen peroxide water, or mixed solution of NH 4 OH, H 2 O 2 and H 2 O into contact with the resist. The step of cleaning (S 25 a ) brings mixed solution of sulfuric acid and hydrogen peroxide water, or mixed solution of NH 4 OH, H 2 O 2 and H 2 O into contact with the principal face of the solid substrate. The step of removing a resist (S 28 ) and the step of cleaning (S 25 a ) can be conducted simultaneously by bringing mixed solution of sulfuric acid and hydrogen peroxide water, or mixed solution of NH 4 OH, H 2 O 2 and H 2 O into contact with the principal face of the solid substrate.
1. A method of forming an impurity introducing layer, comprising the steps of:
(a) forming a resist pattern on a semiconductor substrate;
(b) amorphousizing a surface of the semiconductor substrate after step (a);
(c) introducing impurities to the semiconductor substrate by a plasma doping using a gas containing the impurities and using the resist pattern as a mask;
(d) removing the resist pattern after step (c);
(e) cleaning the semiconductor substrate after step (d); and
(f) heating the semiconductor substrate to activate the impurities after step (e).
2. The method according to claim 1 , wherein the gas containing the impurities is one of a hydrogen compound gas containing boron, a fluoride gas containing boron, and a chloride gas containing boron.
3. The method according to claim 1 , wherein a depth at which the atomic concentration of the impurities in the semiconductor substrate is 1×10 18 atoms/cm 2 before the heat treatment is 15 nm or less.
4. The method of according to claim 1 , wherein a pressure of the plasma doping is in the range of 0.9 to 2.5 Pa.
5. The method according to claim 1 , further comprising the step of (f) forming an oxidation film on the semiconductor substrate to which the impurities are introduced, after step (c) and before (e).
6. The method according to claim 1 , wherein the resist pattern is removed and an oxidation film is formed on the semiconductor layer to which the impurities are introduced in step (e).
7. The method according to claim 1 , wherein step (d) is performed by using an oxygenic plasma.
8. The method according to claim 1 , wherein step (d) is performed by using a solution in which sulphuric acid and hydrogen peroxide are mixed.
9. The method according to claim 1 , wherein the heat treatment is performed by using a halogen lamp.
10. The method according to claim 1 , wherein step (d) is performed by using one of a solution in which sulphuric acid and hydrogen peroxide are mixed and a solution in which NH 4 OH, H 2 O 2 , and H 2 O are mixed.
11. The method according to claim 1 , wherein step (e) is performed by using one of a solution in which sulphuric acid and hydrogen peroxide are mixed and a solution in which NH 4 OH, H 2 O 2 , and H 2 O are mixed.
12. The method according to claim 1 , wherein steps (d) and (e) are performed together by using one of a solution in which sulphuric acid and hydrogen peroxide are mixed and a solution in which NH 4 OH, H 2 O 2 , and H 2 O are mixed.
13. The method according to claim 1 , wherein step (d) is performed by using an oxygenic plasma and the step (e) is performed by using one of a solution in which sulphuric acid and hydrogen peroxide are mixed and a solution in which NH 4 OH, H 2 O 2 , and H 2 O are mixed.
14. The method according to claim 1 , wherein step (d) is performed by oxygen plasma.
15. The method according to claim 1 , wherein the step (c) is performed at the same time as the step (b).
16. The method according to claim 1 , wherein the gas containing the impurities is a mixture gas of B 2 H 6 and He.
17. The method according to claim 16 , wherein a concentration of the B 2 H 6 is in the range of 0.025 to 5%.
18. The method according to claim 1 , wherein the heat treatment is performed by using a spike RTA.
19. The method according to claim 1 , wherein the step (c) is performed after the step (b).
20. The method according to claim 19 , wherein the step (b) is performed by using a plasma irradiation.
21. The method layer according to claim 1 , wherein the plasma doping is an ion-mode plasma doping.
22. The method according to claim 21 , wherein the surface of the semiconductor substrate is made amorphous by the ion-mode plasma doping in step (c).
23. The method according to claim 21 , wherein the gas containing the impurities is a mixture gas of B 2 H 6 and He, and a concentration of the B 2 H 6 is 0.7% or less.
24. The method according to claim 22 , wherein the gas containing the impurities is a mixture gas of B 2 H 6 and He, and a concentration of the B 2 H 6 is in the range of 0.05 to 0.1%.