Method for establishing mapping relation in STI etch and controlling critical dimension of STI
US9666472B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 29, 2016 |
| Grant date | May 30, 2017 |
| Priority date | — |
| Expiry date | Mar 29, 2036 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L22/12
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
The present invention provides a method for controlling a critical dimension of shallow trench isolations in a STI etch process, comprises the following steps: before the STI etch process, pre-establishing a mapping relation between a post-etch and pre-etch critical dimension difference of a BARC layer and a thickness of the BARC layer; and during the STI etch process after coating the BARC layer, measuring the thickness of the BARC layer and determining a trimming time for a hard mask layer according to a critical dimension difference corresponding to the measured thickness in the mapping relation and a critical dimension of a photoresist pattern, then performing a trimming process for the hard mask layer lasting the trimming time to make a critical dimension of the hard mask layer equal to a required critical dimension of an active area, and etching a substrate to form shallow trenches with a predetermined critical dimension.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.