Device Fabrication

Within the compass of this field we have several goals and a broad range of equipment. The semiconductor device processing and fabrication facilities include a photolithography system with 5mm spatial resolution, a Plasma-Therm Series 790 ICP dry etching system, thermal annealing furnaces, a thermal evaporation system, and a wire bonder.  The physical realization of microcavity devices based on GaN, AlGaN, and InGaN epilayers, heterostructures, and multiple quantum wells is achieved by photolithographic patterning and plasma etching technique. Our goal is to proceed from GaN production to actually creating working devices from the raw material such as: light emitting diodes, microlasers, transistors, and so on.

Below: A picture of the ICP

Below: A picture of the wire bonder and of the rapid thermal annealing furnace

Below: Various Instrumentation for Device Fabrication and Testing:

Photolithography System, Hood, Optical Microscope, probe stations and micro-manipulators; I-V tracer.

Below: (a) SEM image of a microdisk array fabricated from p-GaN/InGaN/n-GaN quantum wells at KSU. This array is a microdisplay when the disks are individually addressed and forward biased and is a miniaturized detector array when the disks are reversed biased;  (b) Optical microscope image of a bonding scheme that allows us to address each microcavity pixel individually (or a III-nitride blue microdisplay); (c) Optical microscope image of the III-nitride blue microdisplay [Fig. (b)] in action, displaying letters "KSU"; (d) Power output vs. input current for three individual micro-LEDs within
the microdisplay Fig. (b) and the inset shows the electroluminescence spectrum of these micro-LEDs.