Process for producing a structured mask
US5876880A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 25, 1997 |
| Grant date | Mar 2, 1999 |
| Priority date | — |
| Expiry date | Nov 25, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F1/20
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A process is disclosed for producing a structured mask for use in reproducing structures of that mask on an object with the aid of electromagnetic or particulate radiation, in particular for ion beam lithography. A flat smooth substrate of more than 20 .mu.m in thickness is selected and a thin diaphragm is produced from that substrate by etching one of the sections removed from the edging to a depth of c. 0.5-20 .mu.m, the tensile stress within the diaphragm being greater than 5 MPa. Lithographic structures are then formed on a central region of the diaphragm with a tensile stress of more than 5 MPa; apertures are etched into the diaphragm to form the mask structures and the effective thickness inside a diaphragm region substantially enclosing the mask structures is reduced, causing the central region containing the structures to be joined to the substrate edging elastically in such a way that the mean tensile stress within this central region is reduced to below 5 MPa. The region with reduced effective thickness preferably takes the form of a peripheral channel or at least one perforation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.