Method for reversing tone or polarity of pattern on integrated circuit substrate utilizing reverse casting by planarization
US4973544A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 7, 1989 |
| Grant date | Nov 27, 1990 |
| Priority date | — |
| Expiry date | Mar 7, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/033
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
The tone or polarity of a patterned layer such as a photoresist mask on an integrated circuit or device substrate is reversed with substantially perfect alignment. A liquid planarizing layer is formed and hardened onto the patterned layer and underlying substrate, filling in spaces between pattern areas. The planarizing layer is then etched to a sufficient depth to expose the patterned layer. Finally, the patterned layer is dissolved away, leaving the reversed tone image which is constituted by the planarizing material in the spaces which were filled in. Modified embodiments enable large spaces between original pattern areas to be effectively reversed, and multi-level reversed tone images to be formed in which the reversed tone layers are thicker than the original layers.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.