Gallium arsenide transistors: realization through a molecularly designed insulator

Area of Science:

• Materials Science
• Semiconductor Physics
• Electrical Engineering

Background:

• Silicon-based transistors dominate the electronics industry.
• Gallium Arsenide (GaAs) offers potential for high-speed electronic devices.
• Development of reliable insulator materials for GaAs transistors is crucial.

Purpose of the Study:

• To fabricate and characterize a novel GaAs-based field-effect transistor (FET).
• To evaluate the performance of cubic Gallium Sulfide (GaS) as an insulator in GaAs FETs.
• To compare the performance metrics of the fabricated GaAs FET with commercial silicon devices.

Main Methods:

• Fabrication of an n-channel, depletion mode GaAs FET using vapor-deposited cubic GaS as the insulator.
• Characterization of transistor parameters including channel mobility, interfacial trap density, and transconductance.
• Measurement of the on-to-off resistance ratio.

Main Results:

• Achieved a high channel mobility of 4665.6 cm²/Vs.
• Determined an interfacial trap density of 10¹¹ eV⁻¹cm⁻².
• Obtained a transconductance of 7 mS for a 5 μm gate length at 8 V gate voltage.
• Demonstrated an on-to-off resistance ratio comparable to commercial devices.

Conclusions:

• Cubic GaS is a viable insulator material for high-performance GaAs transistors.
• The fabricated GaAs FET demonstrates excellent electrical characteristics.
• This development paves the way for advanced GaAs-based electronic applications.