Method of fabricating devices using an attenuated phase-shifting mask and an attenuated phase-shifting mask
US6251546A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 16, 1999 |
| Grant date | Jun 26, 2001 |
| Priority date | — |
| Expiry date | Sep 16, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F1/32
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An improved attenuated phase-shifting mask (APSM) for use with an imaging tool for forming a patterned feature on a photoresist layer of a semiconductor wafer. The APSM has a transmissive region for substantially transmitting light therethrough to form a projected image substantially shaped as the patterned feature on the photoresist layer. The APSM also has an attenuating and phase-shifting region, contiguous with the transmissive region, for absorbing a portion of the light incident thereon and for shifting the phase of the incident light by a predetermined number of degrees relative to that of the light transmitted through the transmissive region so as to destructively interfere with the light transmitted through the transmissive region and to project a background image. The transmissive region has a dimension d dimensioned such that the intensity of the image projected by the transmissive region is darker than the intensity of the background image projected by the attenuating and phase-shifting region of the mask and that the intensity of the background image is substantially uniform.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.