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US 11,447,876 B2Granted
High-precision etching method
AssigneeInstitute of Microelectronics, Chinese Academy of Sciences
InventorsHuilong Zhu, Xiaogen Yin, Chen Li, Anyan Du, Yongkui Zhang
Life of this patent
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Abstract
An embodiment of the present disclosure provides an etching method, having the following steps: forming a modified layer having a thickness of one or several atom layers on a selected region of a surface of a semiconductor material layer by using a modifier; and removing the modified layer. When a semiconductor is processed, this method achieves precise control over the etching thickness and improves the etching rate at the same time.
Claims19
A selective etching method, comprising:
- a step of forming a modified layer having a thickness of one or several atom layers on a selected region of a surface of a semiconductor material layer by using a modifier, wherein the semiconductor material layer comprises Si as a first solid material and SiGe as a second solid material, the selected region includes an exposed surface of the first solid material and an exposed surface of the second solid material, a rate of forming the modified layer on the surface of the second solid material is greater than a rate of forming the modified layer on the surface of the first solid material, so that the modified layer on the surface of the second solid material has a thickness greater than that of the modified layer on the surface of the first solid material;
- and
- a step of removing the modified layer, wherein the modified layer on the surface of the first solid material and the modified layer on the surface of the second solid material are etched simultaneously, until the modified layer on the surface of the second solid material is removed completely.
Dependencies are inferred from the claim text.