Browse Prior Art Database

MEANS AND METHOD FOR CLEANING SEMICONDUCTOR WAFERS

IP.com Disclosure Number: IPCOM000005696D
Original Publication Date: 1988-Oct-01
Included in the Prior Art Database: 2001-Oct-26
Document File: 2 page(s) / 100K

Publishing Venue

Motorola

Related People

Donald L. Tolliver: AUTHOR [+2]

Abstract

There is a need for improved means and methods for cleaning the surfaces of integrated circuit wafers during manufacturing. A variety of different cleaning systems have been developed in the prior art to reduce the level of contamination on silicon wafers. However, with many prior art cleaning systems and methods, con- tamination is actually added to the surface rather than removed.

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m MOTOROLA Technical Developments Volume 8 October 1988

MEANS AND METHOD FOR CLEANING SEMICONDUCTOR WAFERS

by Donald L. Tolliver and Jacob A. Schaper

   There is a need for improved means and methods for cleaning the surfaces of integrated circuit wafers during manufacturing. A variety of different cleaning systems have been developed in the prior art to reduce the level of contamination on silicon wafers. However, with many prior art cleaning systems and methods, con- tamination is actually added to the surface rather than removed.

   A unique cleaning system and method has been developed which provides reduced particle and ionic con- tamination on semiconductor wafers. While the individual steps and subsystems use conventional chemical processes, they are carried out in a way that produces results which are much superior to methods of semicon- ductor wafer cleaning.

SYSTEM AND METHOD STEPS

The major components and process steps are as follows. The sequential cleaning stations or steps are shown in FIG. 1. The apparatus has eight possible cleaning stations. Not all are used.

Station 1:

Hot (125°C) recirculating sulfuric acid bath with direct ozone injection into the acid, with continuous
0.1 micron filtration at 3 to 6 gallons per minute, and with insitu continuous real time submicron
(0.3 urn) particle monitoring.

Automated D.I. water rinse with 0.1 and 0.04 micron filtration at 8 to 10 gallons per minute minimum. It is important to keep the flow rate in the rinse bath in the recommended range.

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Room temperature recirculating 50:1, HzO:HF, etch bath with 0.1 micron filtration and insitu real time submicron particle monitoring.

First tank of a two level hot D.I. water cascade at approximately 85.90°C.

Second tank of the two level hot D.I. water cascade. This step may be omitted.

Direct hot nitrogen gas drying after rinsing and placement in a closed and covered stainless steel drying chamber. Drying continues until no visible water drops are present on t...