Browse Prior Art Database

Wafer Cleaner System

IP.com Disclosure Number: IPCOM000076464D
Original Publication Date: 1972-Mar-01
Included in the Prior Art Database: 2005-Feb-24
Document File: 2 page(s) / 46K

Publishing Venue

IBM

Related People

Moreau, W: AUTHOR [+2]

Abstract

Shown is a system to prevent ion residue and other contaminates which are left behind by evaporation of normal final deionized (DI) water rinse of wafers at various stages of processing. The system can be used after normal cascade rinsing with DI water, by rinsing with an azeotropic mixture in a conventional vapor degreaser set up, where vapor can condensate on cooler wafer surfaces and wash off last traces of residues prior to the next processing step. Any condensate remaining is contemplated to be blown off with clear air supply and not allowed to evaporate to ensure cleanest surface.

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Wafer Cleaner System

Shown is a system to prevent ion residue and other contaminates which are left behind by evaporation of normal final deionized (DI) water rinse of wafers at various stages of processing.

The system can be used after normal cascade rinsing with DI water, by rinsing with an azeotropic mixture in a conventional vapor degreaser set up, where vapor can condensate on cooler wafer surfaces and wash off last traces of residues prior to the next processing step. Any condensate remaining is contemplated to be blown off with clear air supply and not allowed to evaporate to ensure cleanest surface.

n azeotropic propionic acid/water mixture boiling at 100 Degrees C provides the required surfactant action to remove adhered mineral particles not removed or deposited from deionized water rinses. The recycling action of the vapor bath requires small amounts of materials to accomplish the cleaning in contrast to a rinse-type operation.

Typical formulations of effective azeotropic mixtures found effective in imparting desirable cleaning properties to the vapors are:
A. 82% water/18% propionic acid boiling at 100 Degrees C at

760 mm's;
B. 43% pyridine/50% water azeotrope.

The water/pyridine azeotrope was also found very effective for stripping AZ- 1350* resist, since the pyridine/water mixture is a basic organic amine solution with a pH of 14.0.

In addition, other azeotropic mixtures contemplated are a 79% butyric acid/21% water, as well as stearic acid/water mi...