Chemical composition for tri-layer removal
US11378882B2 · kind B2 · utility
1Cited by
13References
20Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Aug 31, 2020 |
| Grant date | Jul 5, 2022 |
| Priority date | — |
| Expiry date | Aug 31, 2040 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/76811
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method includes forming a tri-layer. The tri-layer includes a bottom layer; a middle layer over the bottom layer; and a top layer over the middle layer. The top layer includes a photo resist. The method further includes removing the top layer; and removing the middle layer using a chemical solution. The chemical solution is free from potassium hydroxide (KOH), and includes at least one of a quaternary ammonium hydroxide and a quaternary ammonium fluoride.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.