Precision Cleaning/Submicron Level Cleaning With Liquid/Supercritical CO2 Technology

EPA Contract Number: 68D99050
Title: Precision Cleaning/Submicron Level Cleaning With Liquid/Supercritical CO2 Technology
Investigators: Jafri, Ijaz H.
Small Business: GT Equipment Technologies Inc.
EPA Contact: Manager, SBIR Program
Phase: I
Project Period: September 1, 1999 through March 1, 2000
Project Amount: $70,000
RFA: Small Business Innovation Research (SBIR) - Phase I (1999) RFA Text |  Recipients Lists
Research Category: SBIR - Pollution Prevention , Pollution Prevention/Sustainable Development , Small Business Innovation Research (SBIR)


This Phase I project is aimed at developing a viable supercritical carbon dioxide SCCO2-based technology for semiconductor and microelectromechanical systems (MEMS) wafer cleaning and drying. The proposed technology will replace the wet processing by using CO2- based processing techniques. The current cleaning techniques used in standard semiconductor and MEMS fabrication lines rely on the use of chemicals that are toxic, hazardous, and environmentally nonfriendly. These techniques contaminate tremendous amounts of water. Recent studies conducted by the Los Alamos National Laboratory have indicated that photoresist removal is possible when supercritical CO2 is used in combination with a cosolvent. GT has manufactured a proven (patent pending) prototype supercritical CO2 system for wafer drying/cleaning. To make pioneering contributions to the CO2-based wafer processing technology, further research and development is crucial. This project will investigate the feasibility of a CO2-based system by performing experiments on particulate removal from silicon wafer, modeling of dynamics of flow inside the pressure chamber, and characterization of processed wafer. Once successful results are achieved, preliminary design of the next generation CO2-based wafer processing station will be prepared, with detailed engineering, manufacturing, and testing in Phase II.

This project is aimed at semiconductor and MEMS industries. Wafer cleaning is an essential process in semiconductor manufacturing. A typical wafer goes through a cleaning process 16 to 40 times and another 4 to16 times for photoresist stripping. Particulate contamination of the wafer during these process steps is always an issue. Processes, such as photoresist stripping, involve the use of separate systems. If successfully developed, the proposed technology will have the capability of replacing wafer cleaning stations (that typically use toxic chemicals and substances), which is a $2 billion projected (1999) market. Also, the technology will have the capability to reduce clean room space because more than one process can be achieved in a single system. Thus, the proposed technology has tremendous commercial potential in a market that has a projected sales of more than $161 billion before the turn of the century.

Publications and Presentations:

Publications have been submitted on this project: View all 3 publications for this project

Journal Articles:

Journal Articles have been submitted on this project: View all 1 journal articles for this project

Supplemental Keywords:

small business, SBIR, pollution prevention, chemistry, EPA., Scientific Discipline, Waste, Water, Sustainable Industry/Business, cleaner production/pollution prevention, Chemistry, Technology for Sustainable Environment, New/Innovative technologies, Engineering, Hazardous, Engineering, Chemistry, & Physics, microelectromechanical systems (MEMS), particulates, supercritical carbon dioxide (SCCO2) technology, clean technologies, clean technology, semiconductor industry, hazardous materials, wafer cleaning, process modification, wet cleaning alternatives, innovative technology, semiconductor manufacturing, CO2 - based systems, hazardous chemicals, pollution prevention

Progress and Final Reports:

  • Final Report