Left; the design for an experimental transistor made of β-Ga2O3. Right; an atomic force microscope image of the semiconductor.
Researchers at Purdue University have demonstrated the high-performance potential of an experimental transistor made of a semiconductor called beta gallium oxide β-Ga2O3.
They believe the semiconductor is promising for next-generation power electronics, bringing new ultra-efficient switches to applications such as the power grid, military ships and aircraft.
The transistor, called a β-Ga2O3 on Insulator (GOOI) FET, is especially promising because it possesses an ultra-wide bandgap, a trait needed for switches in high-voltage applications.
Compared to other semiconductors thought to be promising for the transistors, devices made from β-Ga2O3 have a higher breakdown voltage (the voltage at which the device fails) said Peide Ye, Purdue University's Richard J. and Mary Jo Schwartz Professor of Electrical and Computer Engineering.
The findings are detailed in a research paper published this month in IEEE Electron Device Letters. Graduate student Hong Zhou performed much of the research.
The team also developed a new low-cost method using adhesive tape to peel off layers of the semiconductor from a single crystal, representing a far less expensive alternative to epitaxy.
The market price for a 1cm-by-1.5cm piece of β-Ga2O3 produced using epitaxy is about $6,000. In comparison, the 'Scotch-tape' approach costs pennies and it can be used to cut films of the material into belts or βnano-membranesβ which can then be transferred to aconventional silicon disc and manufactured into devices, Ye said.
The technique was found to yield extremely smooth films, having a surface roughness of 0.3nm, which is another factor that bodes well for its use in electronic devices, said Ye, who is affiliated with the NEPTUNE Center for Power and Energy Research, funded by the US Office of Naval Research.
The Purdue team achieved electrical currents 10 to 100 times greater than other research groups working with the semiconductor, Ye said.
One drawback to the material is that it possesses poor thermal properties. To help solve the problem, future research may include work to attach the material to a substrate of diamond or AlN.
'High Performance Depletion/Enhancement-Mode β-Ga2O3 on Insulator (GOOI) Field-effect Transistors with Record Drain Currents of 600/450 mA/mm'; by Hong Zhou et al; IEEE Electron Device Letters (Volume: 38, Issue: 1, Jan. 2017)