IBM announces world's fastest silicon-based transistor

The transistor, a key component in microchips, uses a modifieddesign and IBM's proven silicon germanium (SiGe) bipolar technology toachieve speeds of 350 GigaHertz (GHz). IBM's new transistor performsnearly 300 percent faster than today's production devices, and is 65percent faster than previously reported silicon transistors. Afingernail-sized microchip can hold millions of transistors.

IBM anticipates the new transistor will lead to communications chipswith speeds of more than 150 GHz in about two years. The transistor isalso expected to result in substantially lower power consumption andlower cost for communications systems and other electronicproducts.

"The industry recognizes the importance of SiGe technology, andeveryone is racing to add it to their arsenal," said Bernard Meyerson,IBM Fellow and Chief Technologist, IBM Technology Group. "SiGe isimperative for true system-on-chip designs that pull together standardlogic circuitry and higher-speed wireless communications circuitry. Andwhile others are introducing their first versions, this is IBM's fifthgeneration of SiGe technology."

IBM will present details of the technology in a paper, titled "SiGeHBTs with Cut-off Frequency Near 300 GHz" at the International ElectronDevices Meeting (IEDM) held in San Francisco, Dec. 9-11, 2002.Transistor speeds are determined primarily by how quickly electronspass through them. This is dependent on the semiconductor material usedto fabricate the transistor and the distance electrons must travelthrough it. The material used in most standard transistors is silicon.In 1989, following pioneering research work conducted at IBM's ResearchDivision, IBM introduced an improvement to the silicon by addinggermanium to speed electrical flow, improving performance and reducingpower consumption. With this new achievement, IBM is combining the useof the SiGe material with an improved transistor design that canshorten the electrical path to help speed up the device.

In standard complementary metal oxide semiconductor (CMOS)transistors, electrons travel horizontally, so shortening the pathrequires that the transistor be made narrower. This is an increasinglydifficult and expensive task that requires new manufacturing tools. Inthis case, IBM has employed a bipolar transistor - a differenttransistor configuration that is critical for chips to drive high-speedwireless communications products. In bipolar transistors, electronstravel vertically, so the speed can be improved by reducing the height- rather than the width - of the transistor. IBM used a novel verticalprofile scaling technique to reduce the height of the transistor,shortening the path of electrical flow and helping improveperformance.

IBM's SiGe chips are built on existing manufacturing lines, allowingthe technology to be introduced rapidly and at minimal cost. This hasexpanded the use of SiGe technology for extending function and batterylife in cellular phones and other RF (radio frequency, or wireless)communications products. IBM manufactures SiGe chips at its Burlington,Vt., facility. In data published by research firm IC Insights in its"2002 McClean Report," the firm estimates that SiGe sales totaled $320million in 2001 and are projected to grow to about $2.7 billion by2006. The report estimates that IBM SiGe activity accounted for morethan 80 percent of total 2001 SiGe business.

About IBM Microelectronics

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