Katherine J. Herrick

W-band metamorphic HEMT with 267 mW output power

This paper reports the highest W-band power output of metamorphic HEMT (MHEMT) technology to date. 267 mW single stage performances at 90 GHz are achieved on a 0.15 micron GaAs-based production line with improved manufacturability over InP HEMT. The single stage circuits presented here are building blocks for future MHEMT power amplifier development.

95 GHz metamorphic HEMT power amplifiers on GaAs

This paper reports on the first 95 GHz metamorphic HEMT power amplifier demonstration including power as a function of temperature. Two power MHEMT materials with 53% and 53%/43% indium channels are investigated showing a slight advantage to the split channel material. At 95 GHz, G/sub max/ values ranging 8.25-10.8 dB are shown for both materials. Single stage 0.15 mm periphery amplifiers using single 4/spl times/37.5 /spl mu/m FETs show >10 dB small signal gain. Two dB compressed power data at 95 GHz yields 15.3 dBm (224 mW/mm) and PAEs up to 22.8%. Increasing temperature up to 80/spl deg/C results in output power and PAE degradation of only 0.43 dB and 2.6 percentage points, respectively. These promising results are on the path to 100-300 mW MHEMT power amplifiers at W-band with improved manufacturability over InP HEMT.

W-Band Oscillator on Metamorphic HEMT

We present for the first time an un-buffered W-band oscillator on a metamorphic HEMT GaAs substrate. The oscillator has an output power of +1.5 dBm and a phase noise of -101 dBc/Hz at a 1 MHz offset. This oscillator will be part of an integrated monolithic front end

S-Ku band intelligent amplifier microsystem

Progress-to-date of a S-Ku band intelligent amplifier microsystem is presented. Performance objectives are 0.5 Watt with 30%-55% power added efficiency across the band using a total of 10 RF MEMS. GaAs-to-GaAs and Borosilicate-to-GaAs low temperature (<250C) indium-gold wafer bonding is employed to provide hermeticity and integration of the pHEMT transistor with the RF MEMS. The compact mixed signal microsystem, 2 inches by 3 inches, utilizes an existing data processor with an intelligent control algorithm which optimizes the input and output circuit matching networks for optimal performance.

W-band power metamorphic HEMT technology on GaAs

Our 0.15 um power MHEMT development at W-band includes comparison of single (53%) and split channel (53/43%) material. Preliminary single stage microstrip amplifier results yield 225 mW/mm and >10dB small signal gain at 95 GHz.

Thermal considerations for advanced SOI substrates designed for III-V/Si heterointegration

The thermal budget/integration challenges for SOLES have been investigated. A process window has been found that allows for the successful demonstration of a monolithically integrated III-V/Si differential amplifier. A method of increasing the integration flexibility of SOLES by introducing SiNx interlayers has been demonstrated. Future work will explore the increased thermal budget/integration flexibility of SOLES provided by incorporating embedded GaAs layers.

Monolithic III-V/Si integration

We summarize our work on creating substrate platforms, processes, and devices for the monolithic integration of silicon CMOS circuits with III-V optical and electronic devices. Visible LEDs and InP HBTs have been integrated on silicon materials platforms that lend themselves to process integration within silicon fabrication facilities. We also summarize research on tensile Ge, which could be a high mobility material for III-V MOS, and research on an in-situ MOCVD Al2O3/GaAs process for III-V MOS.

MBE growth of InP-HBT structures on Ge-on-insulator/Si substrates by MBE

MBE growth of InP-based HBTs on GeOI/Si substrates is described. A GaAs buffer is nucleated on the GeOI; then a graded InAlAs metamorphic buffer transitions the lattice constant to InP. TEM shows minimal anti-phase boundaries and limited dislocations propagating into the device layers. Large area DC parameters are similar to LM HBTs grown on InP. Small area devices exhibit peak current gain cutoff frequency (ft) of 170 GHz at 2 mA/mum2 nominal collector current density. Initial work involving selective epitaxial growth on patterned Ge substrates for future integration is also discussed.