X-ray photolithography

• US 4,028,547 A
• Filed: 06/30/1975
• Issued: 06/07/1977
• Est. Priority Date: 06/30/1975
• Status: Expired due to Term

• Current Assignee: Bell Telephone Laboratories, Inc. (Nokia Corporation)
• Original Assignee: Bell Telephone Laboratories, Inc. (Nokia Corporation)
• Inventors: Eisenberger, Peter Michael
• Primary Examiner(s): Church, Craig E.
• Application Number:
  US05/591,695
• Time in Patent Office: 708 Days
• Field of Search: 250/492 R, 250/492 A, 250/280, 250/272, 250/276, 250/273
• US Class Current: 378/34
• CPC Class Codes: G03F 7/702 Reflective illumination, i.e. reflective optical elements other than folding mirrors, e.g. extreme ultraviolet [EUV] illumination systems
• CPC Class Codes: G03F 7/70575 Wavelength control, e.g. control of bandwidth, multiple wavelength, selection of wavelength or matching of optical components to wavelength
• CPC Class Codes: H01J 37/30 Electron-beam or ion-beam tubes for localised treatment of objects

Abstract

Photolithography of microcircuits with elements in the micrometer size range is performed with X-ray exposure of photoresist layers through electron beam generated shadow masks. Synchrotron radiation from a particle accelerator is used as an intense source of well collimated X-rays and Bragg reflection from a mosaic crystal is used to provide spectral purity for good contrast in the exposed photoresist pattern.

Claims

1. Method of photolithographic processing comprising directing a beam of electromagnetic radiation in the wavelength range 1 A to 50 A through a shadow mask, against a device precursor consisting of a substrate and an image forming layer, sensitive to the radiation, producing a change in the cohesiveness of the irradiated portion of the layer CHARACTERIZED IN THAT the radiation is directed against the device precursor by means of Bragg reflection from an inhomogeneously reflecting crystalline body, which inhomogeneously reflecting crystalline body consists of a multitude of crystallites whose angular spread of crystalline orientation is from 10.sup.^-4 radians to 10.sup.^-1 radians of angle, which radiation is synchrotron radiation and which crystalline body is shaped so as to compensate for the angular deviation of the synchrotron radiation and produce a more nearly parallel beam.

2. A method of claim 1 in which the crystalline body is shaped by elastic deformation.

3. Method of photolithographic processing comprising directing a beam of electromagnetic radiation in the wavelength range 1 A to 50 A through a shadow mask, against a device precursor consisting of a substrate and an image forming layer, sensitive to the radiation, producing a change in the cohesiveness of the irradiated portion of the layer characterized in that the radiation is directed against the device precursor by means of Bragg reflection from an inhomogeneously reflecting crystalline body, which radiation is synchroton radiation, and which inhomogeneously reflecting crystalline body consists of a multitude of crystallites whose angular spread of the crystalline orientation is from 10.sup.^-3 radians to 10.sup.^-2 radians of angle.