Mask blank and method of manufacturing photomask
US12326656B2 · kind B2 · utility
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Key dates
| Filing date | Feb 16, 2021 |
| Grant date | Jun 10, 2025 |
| Priority date | — |
| Expiry date | Aug 9, 2042 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/3065
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A mask blank has a structure where a thin film for pattern formation and a hard mask film are stacked in this order on a transparent substrate, featured in that the thin film is formed of a material containing chromium, the hard mask film includes a stacked structure of a lower layer and an upper layer, the lower layer is formed of a material containing silicon and oxygen, the upper layer is formed of a material containing tantalum and oxygen with an oxygen content of 30 atom % or more, and the ratio of a thickness of the upper layer relative to a total thickness of the hard mask film is 0.7 or less.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.