Sandia and the semiconductor consortium SEMATECH have been partnering since 1989 to help improve the competitiveness of the U.S. semiconductor industry. In 1993 the partnership was formalized through a five-year cooperative research and develop agreement, commonly referred to as a CRADA. This joint collaboration applies Sandia's resources and expertise to solve pre-competitive semiconductor industry problems.

Sandia's electronic capabilities and facilities, unique among U.S. government facilities, make this cooperative research with SEMATECH possible. The enabling facility for the research is the Microelectronics Development Laboratory (MDL), a world-class microelectronics prototyping facility containing state-of-the-art integrated circuit fabrication equipment. With 74,000 square feet, the MDL includes offices, laboratories, and 30,000 square feet of clean-room space with 12,500 square feet of Class 1 clean space in 22 separate clean rooms.

Using the MDL facilities and equipment, Sandia scientists and engineers have completed a variety of projects with SEMATECH during the past five years. These projects have included equipment evaluation, reliability analysis, ergonomics, software quality, manufacturing materials, and control systems.

In congressional testimony, SEMATECH President and Chief Executive Officer William J. Spencer cited Sandia/SEMATECH projects and praised them for finding quick solutions to industry problems. Spencer told members of the Energy Subcommittee of the U.S. House Committee on Science, Space, and Technology that Sandia's modeling expertise had allowed SEMATECH to save "a tremendous amount of time and money" in designing vertical furnaces.

In another project, Spencer said, Sandia accomplished an extensive failure analysis of a pressurized sulfuric acid tank in less than two months. As a result of the Sandia work, the industry was made aware of the problem and a new inspection procedure and design and maintenance changes were recommended. Currently the partnership is addressing three major projects -- contamination-free manufacturing (CFM) research, equipment and process modeling, and equipment benchmarking of U.S. and foreign microelectronics processing equipment.

The SEMATECH Executive Technical Advisory Board (ETAB) has called Sandia's benchmarking work "outstanding" and "a model for the way this activity should be done in the future."

Sandia offers a neutral and easily accessible evaluation site for benchmarking, which is accomplished by adding custom diagnostic instrumentation to basic equipment. The instruments record and map internal operating conditions. Computer controlled data acquisition systems record each detail of the machine's operation. Once the equipment is installed, several evaluations are performed, such as process optimization, marathon testing in a simulated production environment and contamination measurements. This information is used to improve existing and future machines.

The ETAB also praised Sandia's Contamination-free Manufacturing Research Center, which was established to solve defect problems associated with larger die and smaller feature sizes. Universities, equipment suppliers, other national labs, and SEMATECH member companies conduct research at the center that addresses the formation, transport, adhesion, detection, and removal of contaminants in advanced equipment and processes. The initial activities focus on modeling contamination in chemical vapor deposition (CVD) reactors, sensor development, mini and micro environments, and wafer cleaning. Underlying issues are cost of ownership improvements, contamination impact on circuits, and ultra-clean processing.

The research will eventually support circuit feature sizes as small as .1 micron and removal of contamination 10 times smaller -- the size of bacteria. Finding these contaminants on an 8-inch wafer is as difficult as finding a golf ball in an area the size of Rhode Island. Calculations for the flow of particles in a CVD reactor demonstrated the importance of themophoresis in deflecting particles away from the wafer. Low-cost solid state sensors are being developed for insitu detection of trace moisture contamination in gas distribution systems. Experiments using dilute chemical cleaning mixtures in megasonic baths have verified improved particle removal for contamination as small as .15 microns. This results in fewer chemicals and thus lower costs.

Another Sandia/SEMATECH project focuses on low-pressure CVD and plasma process equipment modeling. These models are based on detailed representations of physical and chemical processes occurring in the equipment. They contain gas flow and chemical interactions that help to accurately simulate the topography of the semiconductor surface. A range of computational equipment from personal computers to massively parallel computers support model development and simulation of proposed equipment designs.

Other models are being developed to simulate low- and high-density plasma and rapid thermal processes and equipment. The use of modeling in the design phase shortens the time to market and decreases production costs. It also replaces the empirical development process, allows the evaluation of numerous design alternatives, and optimizes equipment design and control.

A new Equipment Design and Support Center also has been established to help equipment suppliers create better designs and allow faster market release by applying unique Sandia design tools. It also will offer consulting services to assist companies in solving specific problems.

Other Sandia/SEMATECH projects:

• A project to develop methods and computer aids for use by equipment suppliers to improve the reliability and utilization of their equipment by developing general reliability improvement methods with computer modeling tools, and training and assisting suppliers in developing reliability improvement models for their equipment.
• A project to develop, evaluate, and apply advanced materials to fabricate lightweight, modal, and vibration-rigid, low-thermal-response stage components for lithography applications.
• A project to develop in-line cost-effective moisture sensors for corrosive gases and vacuum environments. This involves using laser spectroscopy, absorption spectroscopy, surface acoustic wave sensors, and silicon capacitor microsensor as well as commercial sensors.
• A project to develop an extremely accurate, magnetically levitated, lightweight thermally stable, fine motion stage for semiconductor lithography.