Improved Technique for "Wet-Etching" Aluminum and Metal Surfaces on Integrated Circuits
Original Publication Date: 1995-May-01
Included in the Prior Art Database: 2005-Mar-30
Schieferstein, R: AUTHOR [+1]
Disclosed is a method of etching flat substrates, thereby excluding O(2) bubbles.
Improved Technique for "Wet-Etching" Aluminum
and Metal Surfaces
on Integrated Circuits
a method of etching flat substrates, thereby
excluding O(2) bubbles.
satisfactory solution to the problem of gas-bubble-removal
has been found by facing the wafers in the etching solution to a
nozzle system with variable flow. By means of arranging the nozzle
system within the etching solution, the surface to be etched can be
specifically treated. Thereby the patterns on the printed circuit
card or board can be etched with an accuracy of about 2-3 &mu.m,
since gas bubbles, arising during the etch process, can be carried
away by a shock-wave produced by a circulation pump. By means of
varying the speed of the fluid flow of the shock wave the etch rate
can be optionally controlled.
circulation pump was designed in the way to triple the flow
for a short time to propagate the shock-wave. The wafer agitation
was designed in the way that a chuck moves the wafer up and down,
preferably 60 to 70 times/minute with an amplitude of 50 mm.
combination, destroy gas bubbles and avoid a hold at
the wafer's surface. This system can easily be integrated into
linear handling systems. The Figure schematically shows the
arrangement for etching the wafers.