Process for forming grooves having different depths using a single masking step
US4495025A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 6, 1984 |
| Grant date | Jan 22, 1985 |
| Priority date | — |
| Expiry date | Apr 6, 2004 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/76229
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A process for forming grooves of different depths using a single masking step is presented. In the preferred embodiment of the present invention a photoresist material is used as a single masking layer. The grooves of different types are defined in the masking layer such that the image for a first type groove is narrower in width than the image for a second type groove. The grooves are then formed by subsequent etching steps using conventional etching and anisotropic etching techniques. The grooves are etched to different depths by calculating the proper thickness of a protective layer in relationship to the different groove widths which will allow the deeper groove to be etched without affecting the shallower groove.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.