Etching method and etchant
An etching method for detecting crystal defects, the method includes providing a substrate with an etchant containing hydrogen fluoride, nitric acid, hydrogen chloride, and water. A concave portion on a part having a crystal defect of the substrate is formed by the etchant. The concave portion is examined by a microscope to locate a position of the crystal defect.
1. An etching method for detecting crystal defects, the method comprising:
providing a substrate with an etchant comprising hydrogen fluoride, nitric acid, hydrogen chloride, and water, the substrate having a crystal defect; and
forming a concave portion on the crystal defect by the etchant,
wherein weight composition ratios of hydrogen fluoride, nitric acid, hydrogen chloride, and water in the etchant are (1.7 to 2.4):(30.3 to 49.6):(1.4 to 9.2):(46.5 to 60.1), respectively, and
wherein the etchant does not contain chromium or acetic acid in principle.
2. The method according to claim 1 , further comprising:
using a microscope, locating a position of the crystal defect according to the concave portion.
3. The method according to claim 1 ,
wherein the size of the concave portion is 0.1 μm to 0.3 μm.
4. The method according to claim 1 , further comprising:
forming a film on the part of the substrate having the crystal defect by the etchant; and
removing the film by the etchant to form the concave portion on the substrate.
5. The method according to claim 4 ,
wherein the film is formed by oxidization of the substrate.
6. The method according to claim 1 ,
wherein a treatment time of the substrate by the etchant is 10 seconds to 10 minutes.
7. The method according to claim 1 ,
wherein the etchant does not contain an organic acid in principle.
8. The method according to claim 1 , wherein a weight composition ratio of chromium to H 2 O in the etchant is less than 1:500.
9. The method according to claim 1 , wherein at least one of hydrogen fluoride, nitric acid, hydrogen chloride in the etchant includes ionized molecules.
10. An etching method for detecting crystal defects, the method comprising:
providing a substrate with an etchant comprising an oxidizing agent, an etching agent, hydrogen chloride, and water, the substrate having a crystal defect; and
forming a concave portion on the crystal defect by the etchant,
wherein weight composition ratios of hydrogen fluoride, nitric acid, hydrogen chloride, and water in the etchant are (1.7 to 2.4):(30.3 to 49.6):(1.4 to 9.2):(46.5 to 60.1), respectively, and
wherein the etchant does not contain chromium or acetic acid in principle.
11. The method according to claim 10 , further comprising:
using a microscope, locating a position of the crystal defect according to the concave portion.
12. The method according to claim 10 , wherein the oxidizing agent is nitric acid, and the etching agent is hydrogen fluoride.
13. The method according to claim 10 ,
wherein the size of the concave portion is 0.1 μm to 0.3 μm.
14. The method according to claim 10 ,
wherein a treatment time of the substrate by the etchant is 10 seconds to 10 minutes.
15. The method according to claim 10 ,
wherein the etchant does not contain an organic acid in principle.
16. The method according to claim 10 , wherein a weight composition ratio of chromium to H 2 O in the etchant is less than 1:500.
17. The method according to claim 10 , wherein at least one of hydrogen fluoride, nitric acid, hydrogen chloride in the etchant includes ionized molecules.