Abstract:
(Al/Ga/In)-N compounds namely AlN, GaN and InN with respective bandgaps of 6.2,
3.4 and 0.6 eV constitute the group III nitride family. These wide-range bandgap materials
possess several remarkable properties that make them particularly attractive for reliable solid
state optoelectronic device applications. They have low dielectric constants with high thermal
conductivity pathways, exhibit high bond strengths and high melting temperatures1-3. The large
bond strengths inhibit dislocation motion and improve reliability in comparison to other II-VI
and III-V materials1. In addition, group III-nitrides are resistant to chemical etching and hence
should allow GaN-based devices to be reliably operated in harsh environments4, 5. With large
avalanche breakdown fields, high thermal conductivities, and large high-field electron drift
velocities2, 4, 7-9, various high temperature and high-power microelectronic and optoelectronic
devices such as passivation barriers, ohmic contacts in integrated circuits, blue light-emitting
diodes, candela-class blue-light emitting diodes, green and yellow light-emitting diodes, UV
photodetectors, reflector stacks, high electron mobility transistors, hetero-structure field effect
transistor, metal semiconductor field-effect transistors, and surface acoustic wave devices have
been fabricated. Stimulated emission has been reported from optically pumped GaN and
AlGaInN alloy double hetero-structure films2-4.
