Browse Prior Art Database

Thin Film Coating

IP.com Disclosure Number: IPCOM000090023D
Original Publication Date: 1969-Jan-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 2 page(s) / 62K

Publishing Venue

IBM

Related People

Current, MI: AUTHOR [+3]

Abstract

The method of producing thin uniform coatings in a photoresist overlying a substrate is realized by the formation of standing wave patterns in the photoresist. The standing wave patterns are induced into the photoresist as the result of interaction between incident laser light and reflected laser light along a path. This extends between the point of incidence at the surface of the photoresist and the point of reflection on the reflective surface of the substrate.

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Thin Film Coating

The method of producing thin uniform coatings in a photoresist overlying a substrate is realized by the formation of standing wave patterns in the photoresist. The standing wave patterns are induced into the photoresist as the result of interaction between incident laser light and reflected laser light along a path. This extends between the point of incidence at the surface of the photoresist and the point of reflection on the reflective surface of the substrate.

Substrate 1, with its highly reflective surface 2, is overlaid by photoresist 3. The standing wave pattern is produced by virtue of the interference between the incident and reflected beams, a condition being that a node is developed at the reflecting surface. The first antinode occurs at a quarter wavelength from the boundary surface with successive antinodes occurring at one-half wavelength intervals, forming a multilayered structure throughout the thickness of the photoresist. The calculated and measured layer thicknesses Tally Surf Angstroms, are charted on the right side of the drawing.

All layers above the first layer are removed by overdeveloping. The remaining first layer of one-quarter wavelength thickness contains the master pattern. Dip coating can be used instead of spin coating. Similarly, the pinholes resulting from spin coating are eliminated.

The method reduces the pinhole problem by providing uniform resist thickness with dimensionally stable images and eliminates spinn...