Browse Prior Art Database

Metal Etching Process

IP.com Disclosure Number: IPCOM000122057D
Original Publication Date: 1991-Oct-01
Included in the Prior Art Database: 2005-Apr-04
Document File: 1 page(s) / 48K

Publishing Venue

IBM

Related People

Fredericks, EC: AUTHOR [+3]

Abstract

This article describes a novel metal etching system of equipment and chemicals that is an improvement over current wet metal etching methods.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 100% of the total text.

Metal Etching Process

      This article describes a novel metal etching system of
equipment and chemicals that is an improvement over current wet metal
etching methods.

      This new technique utilizes spray development of etchant,
oxidizing solution and water, with the use of end point detection on
a single wafer etching tool.

      As seen in the figure, a basic aqueous chemical solution, such
as potassium hydroxide, KOH, is contained in a heated reservoir (1)
at 60oC, for example.  Upon tool demand, the KOH solution is admixed
with heated D.I. water to a predetermined concentration (pH) through
a mixing valve (2) and monitored by a pH meter (3).  This mixture is
fed through an ultrasonic nozzle (4), and sprayed on a spinning wafer
(5).  An end point detection system (6) monitors real time etching,
and stops etching when complete.  Valve (7) opens to rinse the wafer
with D.I. water.  At oxidizing solution of potassium permanganate, or
chromic acid, with or without other oxidizers, like peroxides,
contained in a reservoir (8), at some elevated temperature, is
sprayed on the wafer through nozzle (9), to make the photoresist mask
impervious to further degradation by a top layer treatment. This
treatment may be enhanced by exposure to the end point detect light,
especially if this light has a significant deep ultraviolet
component.

      Disclosed anonymously.