ORNL researchers and manufacturing experts from the Oak Ridge Centers for Manufacturing Technology (ORCMT) have teamed with Semiconductor Manufacturing Technology (SEMATECH) to improve the process of manufacturing semiconductors, the computer chips vital to the operation of computers and other electronic components, communications satellites, automobiles, telephone systems and national defense.
"Maintaining our position as the world leader in the semiconductor industry is no small task, given the fact that since the mid-1960s the chip features have been consistently shrinking in size and the chips have been increasing in speed," said Dan Hoffman of ORNL's Radio Frequency Technology Group.
Semiconductor manufacturers use radio frequency power as part of a sophisticated process to produce computer chips. Through the work-for-others contract with SEMATECH, a non-profit research and development consortium of U.S. semiconductor manufacturers and their equipment suppliers, ORNL researchers are providing a radio frequency benchmark facility to evaluate and standardize components used to manufacture chips. Their radio frequency expertise combined with the manufacturing technology resources of ORCMT should be a boon to SEMATECH and the semiconductor industry.
To produce computer chips, manufacturers start with a silicon wafer on which they use a series of masks to project different light patterns onto the wafer. Next, they use radio frequency power to make a plasma from various gases and etch the patterns created by the masks into the wafer. Then they implant conductive ions and deposit insulating oxide films to make transistors. During the process, transistors are connected in specific patterns to form electronic circuits. Chip makers repeat these and other steps from a dozen to 400 times until the chip is completed. To speed the process, manufacturers produce 200 or more chips simultaneously on an 8-inch-diameter silicon wafer.
Over the last three decades, the demand for better, more powerful chips has been tremendous. At the same time, the semiconductor industry is confronted with increasing worldwide competition, so it is facing pressure to keep production costs low. Using techniques and knowledge gained in radio frequency technology over the last couple of decades, ORNL can help the industry meet these demands, Hoffman said. A recent discovery illustrates Hoffman's point.
"SEMATECH sent us radio frequency sub-components for evaluation," said John Caughman, a member of the Radio Frequency Technology Group. "We performed tests on the system and within a few weeks were able to recommend changes that could significantly improve system performance and reliability."
ORNL researchers are also evaluating sensors that measure the amount of radio frequency power generated by various components. It is vital that the amount of radio frequency power reaching the plasma matches the amount called for in the specification for a particular process in making a chip.
"Knowing the exact amount of radio frequency power that is coupled to the plasma is more important than ever because the specifications are becoming increasingly stringent," Caughman said. "The feature sizes - the channels and grooves that are a fraction of the diameter of a human hair - are getting smaller, so the demand for precision is increasing."
Jack Cook, co-director of ORCMT, a nationally recognized manufacturing technology resource, sees this partnership leading to other opportunities. "Working with the semiconductor producers and their equipment suppliers will open new opportunities for our researchers, and some day soon one of these companies may see the value in locating close to this national treasure in radio frequency technology."
The ORNL Radio Frequency Technology Group, which is part of the Fusion Energy Division, acquired much of its knowledge of radio frequency technology through the fusion program. ORNL researchers work closely with ORCMT, which makes use of facilities originally developed for making nuclear weapons components.
"Since opening in 1993, the ORCMT team has helped over 2,000 companies solve manufacturing problems, and this effort for the semiconductor industry is one of the best examples I have seen of applying DOE-developed technology to a highly technical and industrial manufacturing need," Cook said. "It is also an excellent display of the partnership that exists between our research and applied technology organizations."
Funding for the project is provided by SEMATECH and DOE's Defense Programs, Technology Transfer Initiative.
ORNL, one of DOE's multiprogram research facilities, is managed by Lockheed Martin Energy Research Corporation. ORCMT integrates research and development activities of ORNL with manufacturing expertise offered by the Oak Ridge Y-12 Plant, which is managed for DOE by Lockheed Martin Energy Systems.