Method for laterally trimming a hardmask
US9779952B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 21, 2014 |
| Grant date | Oct 3, 2017 |
| Priority date | — |
| Expiry date | Oct 21, 2034 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/31116
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
Techniques herein include methods for controllable lateral etching of dielectrics in polymerizing fluorocarbon plasmas. Methods can include dielectric stack etching that uses a mask trimming step as part of a silicon etching process. Using a fluorocarbon mixture for dielectric mask trimming provides several advantages, such as being straightforward to apply and providing additional flexibility to the process flow. Thus, techniques herein provide a method to correct or tune CDs on a hardmask. In general, this technique can include using a fluorine-based and a fluorocarbon-based, or fluorohydrocarbon-based, chemistry for creating a plasma, and controlling a ratio of the two chemistries. Without the hardmask trim method disclosed herein, if a hardmask CD is not on target, then a wafer is scrapped. With hard-mask trim capability in silicon etch as disclosed herein, a given CD can be re-targeted to eliminate wafer-scraps.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.