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Taper Etching Method of Aluminum Film

IP.com Disclosure Number: IPCOM000112422D
Original Publication Date: 1994-May-01
Included in the Prior Art Database: 2005-Mar-27
Document File: 2 page(s) / 42K

Publishing Venue

IBM

Related People

Arai, T: AUTHOR [+3]

Abstract

Disclosed is a device to control the degree of aluminum taper. As the selectivity of molybdenum and aluminum changes due to the content of phosphoric acid or acetic acid, and as the etching rate is not too fast, smooth and uniform taper with aimed degree is obtainable.

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Taper Etching Method of Aluminum Film

      Disclosed is a device to control the degree of aluminum taper.
As the selectivity of molybdenum and aluminum changes due to the
content of phosphoric acid or acetic acid, and as the etching rate is
not too fast, smooth and uniform taper with aimed degree is
obtainable.

      Etching molybdenum/aluminum film with the mixture of phosphoric
acid, acetic acid, nitric acid and water with much over-etch time,
the taper is made because the etching rate of molybdenum and aluminum
is different.  By changing the amount of each acid or water, the
degree of taper varies.  But the control with the amount of nitric
acid is very difficult.  Because with nitric acid, the influence of
the amount upon the degree of taper is too large to control.  The
control with water is also difficult, because the surface of taper
with little amount of water is not very smooth.  With nitric acid or
acetic acid, the control of taper degree is easy, and the surface of
it is very smooth.  By changing the amount of nitric acid, taper with
10 to 45 degree is made.  By the control with the amount of acetic
acid, 10 to 60 degree is made.