Rca Inc.

General Electric Company

Nancy A Miszkowski

Lawrence K White

Aaron W Levine

An improved process for forming multilayer resist structures for lithographic processing of a substrate having topographical features is provided. The structures are comprised of a resist layer having thereover a layer of poly(vinyl pyrrolidone). When the resist layer is a photoresist, the subject structures may optionally contain an absorptive layer directly overlying the substrate and/or a layer of contrast enhancement material overlying the planarizing layer. The poly(vinyl pyrrolidone) optionally contains from about 0.05 to about 0.1 percent by weight of a suitable surfactant, suitably a nonionic surfactant.

Process of forming a resist structure on substrate having topographical

Nonuniform topographical features on a substrate are effectively coated for lithographic processing by spin-coating with a suitable resin material in a dual spin cycle. The coating material is initially spin-coated onto the substrate at not less than 4000 rpm, preferably from 6000 to 8000 rpm, until build-up of the coating is detectable on a side wall of a topographical feature facing the centrifugal center of the spinning substrate. The spin speed is immediately reduced to less than 4000 rpm, preferably from about 1000 to 3500 rpm, and spinning is continued for a time sufficient to dry the coating. The subject process is particularly suitable for coating a substrate having nonuniform topographical features with a planarizing material.

Spin-coating procedure

Multilayer photoresist recording media containing an absorptive layer are improved by forming the absorptive layer from a composition comprising PMMA or a copolymer of methylmethacrylate and methacrylic acid, certain dyes such as hydroxyazobenzoic acid or Sudan Orange G and a suitable solvent. The dyes are insoluble in the solvent of an overlying photoresist layer. The media are substantially free of loss of resolution due to dissolution of the dye into the photoresist layer.

Absorptive layer for optical lithography

A method for determining the contour of a spin-coated thin film of material, such as a photoresist solution, on an uneven topography, such as a patterned semiconductor wafer, utilizes a pattern of features as isolated, raised lines of different widths. The pattern serves to provide frequency weighted parameters used to estimate the coating conformality on both simple and complex topographies. One parameter indicating the contour is independent of coating thickness and the other parameter suggests the range of feature-to-feature interaction inherent in complex topographies. The pattern is useful as a 'knock-out' portion of a product wafer to monitor the contour of the coating deposited by spun-coated process steps. Orienting the line pattern in radial and tangential position reveals coating thickness relationships dependent on feature orientation with respect to the centrifugal center of the substrate.

Growing community of inventors

Lawrenceville, NJ, United States of America

Nancy A Miszkowski