Forming polysilicon structures

Abstract

A doped polysilicon structure may be formed without the need to etch doped polysilicon. The patterned polysilicon may be covered, an opening may be formed in the polysilicon covering, and then the polysilicon may be doped through the opening. As a result, awkward etching of doped polysilicon may be avoided in some cases.

Description

technical field [0001] The present invention generally relates to the formation of polysilicon structures, including the formation of polysilicon gate electrodes. Background technique [0002] Conventionally, polysilicon gate electrodes are formed by depositing polysilicon on a substrate, which may be covered with a suitable gate dielectric. The polysilicon material is then doped using, for example, an ion implantation process. [0003] The polysilicon electrodes must then be defined from the doped polysilicon layer using etching techniques. However, etching doped polysilicon presents significant challenges. These challenges include known profile issues and differential etch bias issues. [0004] Therefore, there is a need to find a way to form polysilicon structures, such as gate electrodes, without having to etch heavily doped polysilicon material. Contents of the invention [0005] According to a first aspect of the present invention there is provided a method of fo...

AI Technical Summary

Problems solved by technology

However, etching doped polysilicon presents significant challenges

These challenges include known profile issues and differential etch bias issues

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