Browse Prior Art Database

Method for resist material removal for the rework of wafers in lithography using the spin/coater track system

IP.com Disclosure Number: IPCOM000020322D
Publication Date: 2003-Nov-12
Document File: 2 page(s) / 137K

Publishing Venue

The IP.com Prior Art Database

Abstract

Disclosed is a method for resist material removal for the rework of wafers in lithography using the spin/coater track system. Benefits include improved functionality, improved yield, and reduced test wafer consumption.

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Method for resist material removal for the rework of wafers in lithography using the spin/coater track system

Disclosed is a method for resist material removal for the rework of wafers in lithography using the spin/coater track system. Benefits include improved functionality, improved yield, and reduced test wafer consumption.

Background

During wafer processing, resist material removal may be required immediately after lithographic processing prior to etching due to alignment or exposure issues or tool errors. Wafers with exposed metal layers are limited to one ash/rework process step due to reliability issues with asher temperatures and increased average grain size and additional TiAl3 formation between the AlCu and Ti shunt layer. Wafers out of disposition limits that have exceeded the rework limit are scrapped in-line due to reliability concerns. Additionally, the ability of registration tools to measure layer-to-layer alignment is compromised by the roughened surface. In some cases, the use of special doses for reworked material is required to ensure critical dimensions are within control limits.

The use of very clean wafers for defect monitoring of litho tool is a common practice. These wafers have historically only be available for use once since attempting to clean them using an etch asher has left ghost residual images on the wafers and results in too many residual particles.

Conventionally, the standard fabrication process for wafer lithography rework for is comprised of an etch asher to remove resist material prior to reprocessing.

General description

The disclosed method is a process to use lithography track chemicals to completely remove resist material during a rework process. The method uses PBR-40 (ethyl lactate, also ethyl alpha-hydroxypropionate), which is typically part of a lithography track module (backside edge bead removal or EBR) as a method for wafer rework (resist r...