Modification of etch rates by solid masking materials
US4243476A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 29, 1979 |
| Grant date | Jan 6, 1981 |
| Priority date | — |
| Expiry date | Jun 29, 1999 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/32137
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method for etching materials in which a solid, located in the vicinity of the substrate, is used to provide reactive species for etching the substrate. In contrast with prior art etching techniques, an ion beam is provided which strikes a solid source located in the vicinity of the substrate. Reactive gas species are given off by the solid source when it is hit by the ion beam and these species etch the substrate. Etch rates can be enhanced or retarded depending upon the composition of the solid mask. The process has particular utility in etching generally active metals such as Ti, Nb, Ta, NiFe, etc. which undergo a large change in etch rate when mixed gases, such as argon plus O.sub.2, CF.sub.4, CO, or CO.sub.2 (singularly or in combination) are used. As an example, solid TEFLON* can be used to surround the substrate during etching in order to generate active species, such as C and F, for etching of materials such as Ti, Si, NiFe, etc. Conductors and dielectrics can also be etched by this technique. FNT * A trademark of E. I. Du Pont de Nemours.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.