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 μm² 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_T and f_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