Browse Prior Art Database

Device for Semiconductor-Like Processes for Improvement of Wafer Incident Flow

IP.com Disclosure Number: IPCOM000106410D
Original Publication Date: 1993-Nov-01
Included in the Prior Art Database: 2005-Mar-21
Document File: 2 page(s) / 53K

Publishing Venue

IBM

Related People

Thiele, M: AUTHOR

Abstract

This article describes a nitrogen enforced agitation for the process of etching sputter deposited Alsub 2O sub 3 in MR head fabrication.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 68% of the total text.

Device for Semiconductor-Like Processes for Improvement of Wafer Incident Flow

      This article describes a nitrogen enforced agitation for the
process of etching sputter deposited Alsub 2O sub 3 in MR head
fabrication.

      During the process of etching the sputter deposited Al sub 2O
sub 3 in MR head fabrication, the etching bath has to be changed
after about four weeks of use.  Extensive use over double the normal
bath life time showed a strong dependency of the etch rate on the
etch bath agitation.

      Fig. 1 shows the variation of alumina thickness over the time
of use.  After about 45 etch runs the sigma has increased by about
300%.  This increase is directly related to the Nernst diffusion
layer, which is formed by the chosen way of agitation.  To accelerate
a diffusion controlled process this boundary layer has to be as thin
as possible and for a uniform reaction over the total wafer surface
it needs to be nicely distributed.

      To achieve such a uniform and thin diffusion layer the
agitation has to be very turbulent.  This can be done by a simple
addition to the etch tank:  on top of the heat exchanger a set of
plastic tubes (Teflon*) with many drilled holes could be attached to
filter nitrogen gas, which is available in all clean room facilities.
A regulator should be used to adjust the flow and thereby the
strength of the turbulent agitation.

      The plastic tubes can be shaped like a coil or as parallel
lines which is just...