Method of manufacturing photo masks
US11327405B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 26, 2020 |
| Grant date | May 10, 2022 |
| Priority date | — |
| Expiry date | Nov 10, 2040 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F1/78
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
In a method of manufacturing a photo mask for lithography, circuit pattern data are acquired. A pattern density, which is a total pattern area per predetermined area, is calculated from the circuit pattern data. Dummy pattern data for areas having pattern density less than a threshold density are generated. Mask drawing data is generated from the circuit pattern data and the dummy pattern data. By using an electron beam from an electron beam lithography apparatus, patterns are drawn according to the mask drawing data on a resist layer formed on a mask blank substrate. The drawn resist layer is developed using a developing solution. Dummy patterns included in the dummy pattern data are not printed as a photo mask pattern when the resist layer is exposed with the electron beam and is developed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.