Photomask blank, photomask, and method of manufacture
US7736824B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 7, 2007 |
| Grant date | Jun 15, 2010 |
| Priority date | — |
| Expiry date | May 29, 2028 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31616
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
A photomask blank comprising a multilayer film including at least four layers of different compositions, wherein the interface between the layers is moderately graded in composition; a phase shift mask blank comprising a phase shift film of at least two layers including a surface layer of a composition based on a zirconium silicide compound and a substrate adjacent layer of a composition based on a molybdenum silicide compound, and a further layer between one layer and another layer of a different composition, the further layer having a composition moderately graded from that of the one layer to that of the other layer; a phase shift mask blank comprising a phase shift film including a plurality of layers containing a metal and silicon in different compositional ratios which are stacked in such order that a layer having a higher etching rate is on the substrate side and a layer having a lower etching rate is on the surface side. The invention provides a photomask blank, typically a phase shift mask blank, which satisfies optical properties such as transmittance, reflectance and refractive index at an exposure wavelength of interest, and has an etched pattern with a minimal line edg…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.