Method for forming a multi-level reticle
US5914202A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Jun 10, 1996 |
| Grant date | Jun 22, 1999 |
| Priority date | — |
| Expiry date | Jun 10, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F1/50
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A method is providing for making a multi-level reticle which transmits a plurality of incident light intensities, which in turn, are used to form a plurality of thicknesses in a photoresist profile. A partially transmitting film, used as one of the layers of the reticle, is able to provide an intermediate intensity of phase shifted light. The intermediate intensity light has an intensity approximately midway between the intensity of the unattenuated light passing through the reticle substrate layer, and the totally attenuated light blocked by an opaque layer of the reticle. The exposed photoresist receives light at two intensities to form a via hole in the resist in response to the higher intensity light, and a connecting line to the via at an intermediate level of the photoresist in response to the intermediate light intensity. A method for forming the multi-level resist profile from the multi-level reticle is provided as well as a multi-level reticle apparatus.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.