A highly effective technique for etching large batches of GaN wafers, by means of Inductively Coupled Plasma (ICP) tools, has been developed. A variety of 27 × 2 inch wafer batch processes have been investigated and etch rates in excess of 140nm/min with selectivity of 0.9:1 to photoresist (PR) has been achieved.

Particularly, a special active spacer was designed and employed in the ICP system to control plasma profile during the processes. This technique was favourable for increasing etch rates and achieving good uniformities. Using this system a wafer-to-wafer batch uniformity of ±4% was realized.

This paper reviews the reliability results for the gallium nitride on silicon (GaN-on-Si) technologies for commercial and military communications markets. Two technology platforms have been qualified for volume production: one consisting of discrete heterostructure field effect transistors (HFETs) and the other consisting of HFETs integrated with passive components to form monolithic microwave integrated circuits (MMICs). The technology platform qualifications for volume production have been achieved through intrinsic reliability tests on the active and passive device elements as well as extrinsic reliability tests at the product level. This paper presents reliability results on accelerated life test (ALT), high temperature operating life under DC and RF stress (DC/RF-HTOL), electrostatic discharge (ESD), ramped voltage breakdown, electromigration, temperature cycling, robustness under voltage standing wave ratio (VSWR) mismatch conditions, and diode stability. Degradation and breakdown mechanisms are discussed in relation to material properties reliability. The results show that the HFET and MMIC technology platforms display reliable performance for 20 year product lifetime at worst case operating conditions.

Degradation of current gain for ion implanted 4H-SiC bipolar junction transistor is described. The influence of bandgap-narrowing to the collector and base currents of the transistor was investigated using ISE-TCAD simulator. Simulated results show good agreement with the measured results, which show that the common emitter current gain of 3.9 is obtained at a maximum base concentration of 2×1017/cm3 and a maximum emitter concentration of 4×1019/cm3 for ion implanted 4H-SiC BJTs.

Reduction of structural defects in III-nitride based optical devices is of critical importance for high efficient and high reliable optoelectronic performance. Here, three different types of structural defects such as threading dislocations, Mg-related pyramidal defects and columnar defects, observed in GaN-related epitaxial films are described and their relation to reliability of GaN-based LDs is discussed. Composition fluctuations of GaInN MQWs with different In concentrations by analyzed by a laser assisted 3D atom probe are also described.