METHOD OF MAKING PROTECTIVE LAYER OVER POLYSILICON STRUCTURE

摘要

A method includes forming a first polysilicon structure over a first portion of a substrate. A second polysilicon structure is formed over a second portion of the substrate. Two spacers are formed on opposite sidewalls of the second polysilicon structure. A layer of protective material is formed to cover the first and second portions of the substrate. The layer of protective material has a first thickness over the second polysilicon structure and a second thickness over the two spacers. The first thickness is equal to or greater than 500 Å, and the second thickness is equal to or less than 110% of the first thickness. A patterned photo resist layer is formed to cover a first portion of the layer of protective material that covers the first portion of the substrate. The second portion of the layer of protective material is removed.

主权项

1. A method, comprising:
forming a first polysilicon structure over a first portion of a substrate; forming a second polysilicon structure over a second portion of the substrate; forming two spacers on opposite sidewalls of the second polysilicon structure; forming a layer of protective material covering the first portion of the substrate, the first polysilicon structure, the second portion of the substrate, the second polysilicon structure, and the two spacers, the layer of protective material having a first maximum thickness over the second polysilicon structure and a second maximum thickness over the two spacers, the first maximum thickness being equal to or greater than 500 Å, and the second maximum thickness being equal to or less than 110% of the first maximum thickness; forming a patterned photo resist layer covering a first portion of the layer of protective material that covers the first portion of the substrate and exposing a second portion of the layer of protective material that covers the second portion of the substrate; and removing the second portion of the layer of protective material.