New submicron HBT IC technology demonstrates ultra-fast, low-power integrated circuits

A new submicron HBT-based integrated circuit technology has been developed to fabricate transistors as small as 0.2 /spl mu/m/sup 2/ emitter geometry. Using this novel process approach we have been able to reduce our minimum device geometry by a factor of more than ten, and reduce the metallization pitch by a factor of two compared to our baseline process. At the same time, the device RF performance improved by a factor of two. Submicron heterojunction bipolar transistors (HBT's) fabricated with this process exhibited f/sub T/ and f/sub max/ values greater than 165 and 140 GHz, respectively, and dc current gain of over 50. We have also demonstrated several circuits using submicron HBT's in this new IC technology. In particular, a latching comparator circuit which is a key building block of analog-to-digital converters, performed at 40 GHz. It exhibited three times the speed, one-third the dc power, and one-third the chip size of a similar circuit in our baseline process. A single-chip, PLL-based clock and data recovery circuit was fully functional at 4 GHz with a power supply voltage of 2.5 V. It consumed a total dc power of 50 mW, including input and output buffers.