N.X. Nguyen

Power performance and scalability of AlGaN/GaN power MODFETs

The scalability of power performance of AlGaN/GaN MODFETs with large gate periphery, as necessary for microwave power devices, is addressed in this paper. High-frequency large-signal characteristics of AlGaN/GaN MODFETs measured at 8 GHz are reported for devices with gatewidths from 200 /spl mu/m to 1 mm. 1-dB gain compression occurred at input power levels varying from -1 to +10 dBm as the gatewidth increased, while gain remained almost constant at -17 dB. Output power density was /spl sim/1 W/mm for all devices and maximum output power (29.9 dBm) occurred in devices with 1-mm gates, while power-added efficiency remained almost constant at /spl sim/30%. The large-signal characteristics were compared with those obtained by dc and small-signal S-parameters measurements. The results illustrate a notable scalability of AlGaN/GaN MODFET power characteristics and demonstrate their excellent potential for power applications.

Reliability of commercial InP HBTs under high current density lifetests

GCS has successfully developed a high performance and manufacturable 4-inch InP HBT technology for commercial pure-play foundry services. In this paper, we demonstrated that with our proprietary device design and process technology, GCSs InP HBTs show potentially excellent reliability under lifetests at current densities of 100kA/cm/sup 2/ or higher. The V/sub be/s at both low and high current densities have little shift up to 4000hrs under 150kA/cm/sup 2/, which indicates that the C-doped InP HBT is potentially much more stable compared to Be-doped InP HBT for high current density operation. The emitter resistance also shows very stable behavior over the stress time under high current density stresses.

GaN MODFET microwave power technology for future generation radar and communications systems

Abstract In order to gain a better understanding of the role that GaN MODFET technology will play in future generation radar and communications systems, a comparison of the state-of-the-art performance of alternative microwave power technologies will be reviewed. The relative advantages and limitations of each technology will be discussed in relation to system needs. Device results from recent MBE-grown GaN MODFETs will also be presented. In particular, 0.25 μm gate GaN MODFETs grown by MBE have been shown to exhibit less than 5% variation in maximum drain current density (Idmax) from the center to the edge of a 2 inch wafer. This level of uniformity is a substantially higher than that normally found in MOCVD-grown GaN devices (∼28% variation). In addition, evidence is also presented to demonstrate the excellent reproducibility of MBE-grown GaN MODFETs.

Large-signal characteristics of AlGaN/GaN power MODFETs

This work addresses the scalability of power performance of AlGaN/GaN MODFETs with large gate periphery, as necessary for microwave power devices. High-frequency large-signal characteristics of AlGaN/GaN MODFETs have been studied for devices with gate widths from 0.2 to 1 mm. 1-dB gain compression occurred at input power levels varying from -1 to +10 dBm as the gate width increased, while gain remained almost constant at /spl sim/17 dB. Output power density was maximum (1.3 W/mm) for devices with 0. 6 mm gates and maximum output power (29.9 dBm) occurred in devices with 1 mm gates, while power-added-efficiency remained almost constant at /spl sim/30%.

Investigation of reliability for C-doped InP/InGaAs/InP HBTs under high current density operation

Abstrad In this paper, we demonstrated that with our proprietary device design and process technology, GCS’s InP HBTs show excellent reliability under high current density lifetests. Both Va. and emitter resistance are very stable during ISOkA/cm’ stressing, which indicates that the Cdoped InP HBT is potentially much more stable compared lo Be-doped InP HBT for high current density operation. No low activation energy (<O.SeV) failure mode was found for out C-doped InP HBTs. The extracted activation energy is greater than 0.97eV. The estimated MTTF at 125°C is over 3 million hours for device operating at 150kAicmz current density.