Dismiss
InnovationQ will be updated on Sunday, Oct. 22, from 10am ET - noon. You may experience brief service interruptions during that time.
Browse Prior Art Database

Method of Determining the Flow Distribution in a Liquid Tank by Lithographic Means

IP.com Disclosure Number: IPCOM000121473D
Original Publication Date: 1991-Sep-01
Included in the Prior Art Database: 2005-Apr-03
Document File: 2 page(s) / 46K

Publishing Venue

IBM

Related People

Alexander, E: AUTHOR [+2]

Abstract

A method is described by which the flow distribution in a liquid tank is made visible by lithographic means and which is particularly suitable for wafers arranged closely adjacent to each other in a carrier.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 89% of the total text.

Method of Determining the Flow Distribution in a Liquid Tank by Lithographic
Means

      A method is described by which the flow distribution in a
liquid tank is made visible by lithographic means and which is
particularly suitable for wafers arranged closely adjacent to each
other in a carrier.

      Resist developer which is not in a state of equilibrium acts
more aggressively, i.e., at a faster rate, preferably in the
direction of flow, after a sufficiently large resist area has been
developed (sensitized developer).  The developing rate of unexposed
resist varies according to the chemical composition of the respective
resist/developer combination.

      Although the removal rate of unexposed resist is noticeably
lower than that of exposed resist, depending upon the resist system
employed, changes are readily visible from differently coloured thin
layers.

      In a liquid tank containing the developer solution for the
resist, wafers 1 of 4" diameter are arranged at a spacing of about 1
to 2 mm in a carrier 2.  The wafers are resist-coated and
lithographically treated.  The lithographic treatment consists of
exposing an about 1 x 1 cm square in the center of the wafers.  The
size and shape of the exposed area as well as the point of exposure
on the wafer may be adapted, as required.

      Carrier 2, which is open at the bottom, is fitted with two
reciprocally operating magnetic agitators 3 ensuring that the
developer is adequately exchanged, w...