Methods for forming semiconductor structures using selectively-formed sidewall spacers

摘要

Methods for forming semiconductor structures using selectively-formed sidewall spacers are provided. In one method, a first structure and a second structure is formed. The second structure has a height that is greater than the first structure's height. A first sidewall spacer-forming material is deposited overlying the first structure and the second structure. A second sidewall spacer-forming material is deposited overlying the first sidewall spacer-forming material. A composite spacer is formed about the second structure, the composite spacer comprising the first sidewall spacer-forming material and the second sidewall spacer-forming material. The second sidewall spacer-forming material is removed from the first structure and the first sidewall spacer-forming material is removed from the first structure.

主权项

1. A method for forming a semiconductor structure, the method comprising the steps of:
forming a first structure overlying a semiconductor substrate, wherein the first structure has a first height; forming a second structure overlying the semiconductor substrate, wherein the second structure has a second height and wherein the second height is greater than the first height; depositing a first sidewall spacer-forming material overlying the first structure and the second structure; depositing a second sidewall spacer-forming material overlying the first sidewall spacer-forming material, wherein the second sidewall spacer-forming material has an etch rate when subjected to an etchant that is different from an etch rate of the first sidewall spacer-forming material when subjected to the same etchant; etching the first sidewall spacer-forming material and the second sidewall spacer-forming material until a composite spacer is formed about the second structure, the composite spacer comprising the first sidewall spacer-forming material and the second sidewall spacer-forming material; at least substantially removing the second sidewall spacer-forming material from the first structure; and at least substantially removing the first sidewall spacer-forming material from the first structure, wherein the step of etching to form the composite spacer comprises forming about the second structure a composite spacer having a width that is greater than a width of a composite spacer formed about the first structure.