P.5 Electrical Characterization of InGaN materials, for future devices
The first efficient GaN-based semiconductor device was presented no later
than 1993. This was a highly efficient blue light-emitting diode (LED) and
within a few years, a wide range of commercial devices was available, Green
GaN-based LED’s are today used in, e.g. traffic lights and white GaN LED’s
are expected to replace the light bulb as a household light source. The blue
GaN laser diode is used in the next generation of high-density DVD players
(blu-ray DVD). The material can also be used for electrical devices, such
as high-power, high-frequency transistors. The optical and electrical properties
of GaN has an enormous economic and scientific potential, and, as a consequence,
a lot of research is being done on this material.
Despite the progress made in the last decade, a number of problems remain
to be solved. This project targets one of them – the poor knowledge about
the electrical properties of InGaN-materials, used as active regions in most
light-emitting structures.
The project consists in developing low-resistivity contacts to InxGa1-xN,
throughout the composition range. The students will, then, make Hall-effect
samples for electrical characterization of the InGaN-material. The goal is
(a) to find suitable contacts to InGaN material and (b) to gain little-known
knowledge about the electrical properties of InGaN. The processing part of
the project consists of learning and applying common cleanroom techniques
such as masking, etching, metal deposition and annealing. The processed samples
are then characterized by optical microscopy, profilometer, Hall-effect measurements
and other suitable methods.
Contact persons
Thorvald Andersson,
Fredrik Fälth