Ball Semi makes first spherical circuit

Ball Semi makes first spherical circuit
ALLEN, Texas — In an effort to completely reshape chip manufacturing, Ball Semiconductor Inc. today announced it has successfully produced 5-micron, NMOS inverter circuits on one-millimeter spheres of silicon.

The Texas startup aims to reinvent semiconductor manufacturing by developing a radical approach to IC fabrication on silicon balls rather than on flat wafers. Ball Semiconductor, based here, has raised more than $50 million in first-round financing to prove its concepts. The company said it plans to begin work on a pilot line that will eventually result in the production of its first spherical semiconductor products next year.

The first spherical devices were developed after 18 months of intense R&D, said Akira Ishikawa, chairman, chief executive officer and president of Ball Semiconductor. "Until now, we have proven such basic technologies as chemical vapor deposition, spherical lithography and etching individually, but the NMOS spherical semiconductor brings these processes together, producing a feasible product," said Ishikawa, who founded Ball in the fall of 1996 after retiring from Texas Instruments Inc., where he served as president of TI Japan Ltd.

To produce n-channel MOS inverter circuits on silicon balls, the company used a range of processes. These included: spherical single crystallization; spherical surface polishing; integrated circuit design on a sphere with mask data generation and fabrication; spherical lithography with alignment of balls; etching and probe-testing of transistors; spherical resist coating; high-temperature oxidation at 1,300 degrees C; and atmospheric chemical vapor deposition (CVD). Most of these processes are done inside hermetically sealed tubes as silicon balls travel at high speeds without touching the sides of the pipes or each other.

Ball said its attention is now shifting to the development of a pilot line as it moves toward mass production capabilities of spherical semiconductors and sensors.

"We will use the pilot line to test mass production processes for NMOS spherical semiconductors and then progress to the production of CMOS semiconductors, radio frequency devices and MEMS microelectromechnical systems devices," Ishikawa said.

Ball managers figure the spherical semiconductor process can be set up in a plant that costs about $100 million vs. today's $1.5 billion wafer fabs. The company has been offering to license its technology to equipment suppliers and other interested device makers.