Method for forming self-aligned t-shaped transistor electrode
US5288660A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 1, 1993 |
| Grant date | Feb 22, 1994 |
| Priority date | — |
| Expiry date | Feb 1, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/0274
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A T-shaped electrode is formed on a semiconductor substrate by first forming a dielectric film on the substrate. A first layer of photoresist is applied on the upper surface of the dielectric film, and a second layer of photoresist is applied over the first layer of photoresist. The first and second layers of photoresist have different optical properties, requiring different wavelengths of ultraviolet for exposure before developing. Portions of the first and second photoresist layers and the dielectric film are selectively removed by photolithographic techniques with one masking step for forming an opening to the substrate. The first and second photoresist layers adjacent to the opening are ion etched to expose the upper surface of the dielectric film adjacent to the opening. A portion of the first photoresist layer adjacent to the opening is removed to undercut the second photoresist layer. Metal is deposited in the opening and on the exposed upper surface of the dielectric film to form a T-shaped electrode. The first and second photoresist layers are then removed, thereby also removing metal deposited on top of the second layer of photoresist.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.