Multiple exposure masking system for forming multi-level resist profiles
US5753417A · kind A · utility
Assignees
Inventor
Key dates
| Filing date | Jun 10, 1996 |
| Grant date | May 19, 1998 |
| Priority date | — |
| Expiry date | Jun 10, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/70466
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A method is provided for forming multi-level profiles from a photoresist mask. The method includes exposing selected areas of a photoresist layer to two or more different patterns of light at different light dosage levels. For example, one pattern will be exposed to a relatively low dose of light, or to light for a short duration, and a second pattern will be exposed to a relatively high dose of light, or for a greater duration. The plurality of different exposures at different dosage levels occur prior to developing the photoresist. When the photoresist layer is developed, the pattern exposed to a lower dose of light will be etched substantially more slowly than the areas of the photoresist exposed to higher dose of light. By controlling the development process to completely remove the resist in the areas exposed to a high dose of light and only partially remove the resist in the areas exposed to a lower dose of light, a multi-level photoresist profile is formed. Such a multi-level profile can then be used in subsequent semiconductor processing, for example, the formation of interconnects and vias.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.