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Materials for Semitransparent Photomasks

IP.com Disclosure Number: IPCOM000075189D
Original Publication Date: 1971-Aug-01
Included in the Prior Art Database: 2005-Feb-24
Document File: 2 page(s) / 13K

Publishing Venue

IBM

Related People

Sadagopan, V: AUTHOR [+2]

Abstract

HEXAFERRITE PHOTOMASKS.

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Materials for Semitransparent Photomasks

HEXAFERRITE PHOTOMASKS.

PbFe(12)O(19) and BaFe(8)Ga(4)O(19) films, e.g., 1000-3000 Angstroms thick, have been fabricated by chemical vapor deposition, and radio-frequency sputtering techniques have been found to have satisfactory spectral and etching characteristics required for transparent photomask applications. Illustratively, PbFe(12) O(19) is deposited on the radio-frequency heated substrates by pyrolysis of a mixture of lead tetraethyl and iron pentacarbonyl in the presence of air or oxygen. A film useful for masking purposes can be produced in an hour or less.

Hexaferrites such as magnetoplumbite, e.g., PbFe(12)O(19), and barium gallium hexaferrite, e.g., BaFe(8)Ga(4)O(12), are compounds which are representative of a class of hard materials that are opaque in the ultraviolet and transparent in the visible region of the optical spectrum. They are useful as transparent photomasks in the photolithographic technology. PHOSPHOVANADATE PHOTOMASKS.

Three metal ions which show promise for transparent mask applications on basis of their optical absorption are Cr/6+/, V/6+/ and Mn/2+/. Their absorption maxima are at wavelengths of 375, 420 and 430 millimicrons in he optical spectrum, respectively. The above three ions are difficult to incorporate in a film using standard reactive sputtering. This problem can be overcome by choice of phosphovanadate glasses in the following systems: V(2)O(5)-P(2)O(5)- Cr(2)O(3), V(2)O(5)-P(2)O...