Method for treating germanium surfaces and solutions to be employed therein
View Patent ↗The present invention concerns an improved method for treating germanium surfaces in order to reveal crystal defects.
1. A method for treating a germanium substrate, comprising the following steps:
(1) treating a germanium surface of the germanium substrate with an iodine- and bromine-free solution comprising hydrofluoric acid, nitric acid, and acetic acid,
followed by
(2) treating the germanium surface with a solution comprising hydrofluoric acid, hydrogen peroxide, water, and a halogen compound.
2. The method of claim 1 , wherein the solution employed in step (1) consists of hydrofluoric acid, nitric acid, and acetic acid.
3. The method of claim 1 , wherein the solution used in step (2) consists of hydrofluoric acid, hydrogen peroxide, water, and a halogen compound.
4. The method of claim 1 , wherein the halogen compound comprises hydrochloric acid.
5. The method of claim 1 , wherein step (1) is carried out at a temperature in a range extending from 5° C. to 13° C.
6. The method of claim 1 , wherein step (2) is carried out at a temperature in a range extending from 5° C. to 15° C.
7. The method of claim 1 , wherein a rinsing step with deionized water is provided between steps (1) and (2).
8. The method of claim 1 , wherein a volume ratio of hydrofluoric acid to nitric acid in the solution employed in step (1) is from 1:1 to 1:5.
9. The method of claim 1 , wherein a volume ratio of hydrofluoric acid to hydrogen peroxide in the solution employed in step (2) is from 1:1 to 1:5.