Projection electron-beam lithography masks using advanced materials and membrane size
US6261726A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 6, 1999 |
| Grant date | Jul 17, 2001 |
| Priority date | — |
| Expiry date | Dec 6, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J2237/31794
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A stencil or scatterer mask for use with charged particle beam lithography such as projection electron-beam lithography comprises a membrane layer of a material having a Young's modulus of at least about 400 GPa and support struts supporting a surface of the membrane. The struts form and surrounding a plurality of discrete membrane areas of different aspect ratios aligned to design regions of an integrated circuit. The discrete membrane areas have different aspect ratios range from about 1:1 to about 12:1, and the discrete membrane areas have different size surface areas. The membrane is preferably silicon carbide, diamond, diamond-like carbon, amorphous carbon, carbon nitride or boron nitride. When used in scatterer masks, the ratio of discrete membrane area to membrane thickness is at least about 0.18 mm.sup.2 /nm. When used in stencil masks, the ratio of discrete membrane area to membrane thickness is at least about 1.0 mm.sup.2 /nm. The stencil mask is made by depositing a diamond membrane film patterned with a hardmask layer on a substrate, depositing an etch stop layer adjacent the diamond film, and forming supporting struts surrounding a plurality of discrete areas of the me…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.