EL SEGUNDO, CA--- December 4, 1995 - International Rectifier Corporation has developed and placed in operation the industry's first power MOSFET transistor fabrication process that requires only four mask steps.

This significant advance in MOSFET technology means the time needed to manufacture IR's HEXFET(R) power MOSFETs can be reduced by 30%. Only nine days are now needed with four masks to complete a wafer production cycle, compared with 13 that would be required for a six-step process. As a result of this dramatic simplification in semiconductor manufacturing and related improvements in device design, HEXFETs produced with this Fifth Generation process set new benchmark performance standards.

The industry's lowest power MOSFET on-resistance (Rds-on) specifications are achieved by these new products, down to 6 milliohms (maximum) for the N-channel IRL3803, and 20 milliohms (max.) for the P-channel IRF4905. Previous comparable on-resistance ratings were 18 milliohms and 140 milliohms, respectively. Device densities of the new HEXFET family range from four to seven million cells/square inch, depending on voltage.

The 30% improvement in critical device cycle time, while retaining the industry standard planar DMOS technology, is attained by reducing the mask steps to four from six required by International Rectifier's previous fabrication process. Other MOSFET suppliers continue to employ the six-step process, and some require as many as eight steps.

Volume production of the company's advanced line of Fifth Generation HEXFET power MOSFETs is now underway at the new $75 million fabrication facility in Temecula, CA., specifically dedicated to the new process. In addition, advanced IGBTs (Insulted Gate Bipolar Transistors) will be manufactured.

"We regard our four-mask process as the most significant development since the HEXFET 17 years ago, because it sets new standards for power MOSFETs," states Alex Lidow, Chief Executive Officer. "The principal benefit to our customers is faster availability of higher performance products," he adds.

Simplified manufacturing supported by the $75 million IR investment in expanded fab facilities is the key to providing more HEXFETs for customers during a period when power transistor orders far exceed the industry's capacity. "Shorter cycle times, higher throughput and better yields all will aid in supplying more HEXFETs," Lidow states. During the coming calendar year, this improvement will contribute to at least 75% more HEXFETs produced and shipped.

International Rectifier's Fifth Generation HEXFET family includes devices from 20 to 150 volts and current capability ranging from 0.5 Amp in the Micro3 surface-mount package to almost 100A in the TO-220 package. The family will be continuously expanded to offer more than 100 part numbers in both N-channel and P-channel devices.

Development of the new four-step process took place over the past year, stated Dan Kinzer, Vice President of Research and Development. "The ultralow on-resistance and excellent avalanche ruggedness of the new products are achieved with a shallow junction, short channel process made possible by the self-alignment of all diffusions to the polysilicon gate."

The process also features a self-aligned contact process that forms precisely controlled contacts to both source and channel diffusions with only one masking step. While other MOSFET fabrication processes might approach the four-mask Generation 5's performance, none will be able to equal its simplicity.

International Rectifier is a major worldwide supplier of power semiconductors that convert electrical energy to operate power supplies, lighting ballasts and motor drives. Its patented HEXFET power MOSFETs and IGBTs make IR the world leader in field effect transistors. The company's technological advances improve the performance and energy efficiency of electronic and electrical equipment in automotive, lighting, telecom and government/space applications.

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