S.J. Prasad

A 45 GHz AlGaAs/GaAs HBT IC technology

A non-self-aligned HBT (heterojunction bipolar transistor) IC process with f/sub T/ and f/sub max/ of 45 GHz is reported. The process provides 1.4 THz Schottky diodes, nichrome resistors, MIM capacitors, and air-bridge inductors. The process does not use any ion implantation. An HBT prescalar circuit designed with this process clocks at 13.5 GHz. A pulser circuit using Schottky diodes demonstrates 8.6 ps risetime.<<ETX>>

A 45GHz AlGaAs/GaAs HBT IC Technology without Ion-Implantation

A 45GHz HBT IC technology with 1.4THz Schottky diodes is described. The process is mesa isolated and implant-free. The process integrates NiCr resistors, MIM capacitors and air-bridge inductors. A divide-by-eight prescaler shows good performance up to 13.5GHz. A pulser circuit using the Schottky diodes produced a voltage pulse with 10.35ps rise time.

Device testing for the development of an HBT IC process

A description is presented of the DC and microwave testing required for the development of an HBT (heterojunction bipolar transistor) integrated circuit process. Process control monitoring structures have been designed to allow device testing at several stages in processing. Wafer mapping of device parameters shows patterns which can help one to understand the process and improve yield. A database has been set up of device parameters. Examining the relation between various transistor parameters has led to experiments to understand the device current gain and has shown some unexpected results.<<ETX>>