Nuclear reaction transmutation doping in GaN-HEMT MOSFETs

Area of Science:

• Materials Science
• Nuclear Physics
• Semiconductor Device Engineering

Background:

• Gallium Nitride High Electron Mobility Transistors (GaN-HEMTs) are crucial for high-frequency and high-power electronics.
• Controlling dopant concentrations is essential for optimizing GaN-HEMT performance.
• Ion beam irradiation offers a method for material modification and doping.

Purpose of the Study:

• To investigate alpha-induced doping in GaN-HEMTs.
• To identify and quantify the types and populations of dopants created by alpha particle irradiation.
• To theoretically model the nuclear reactions and dopant populations.

Main Methods:

• Irradiation of GaN-HEMTs with a 45 MeV alpha (α) particle beam.
• Analysis of induced activities from nuclear reactions to identify and quantify dopants.
• Theoretical modeling using the TALYS-1.96 nuclear reaction code.

Main Results:

• Identified and quantified both n-type and p-type dopants resulting from alpha irradiation.
• Observed a significant population of Germanium (Ge) and Arsenic (As) isotopes.
• Theoretical modeling using TALYS-1.96 successfully reproduced experimental dopant populations and estimated non-radioactive dopants.
• The generated dopants led to intense n-type doping in the GaN-HEMT semiconductor.

Conclusions:

• Alpha particle irradiation is an effective method for doping GaN-HEMTs.
• The study identified Ge and As as key dopants contributing to n-type conductivity.
• Theoretical modeling provides a valuable tool for predicting dopant populations in ion-beam-modified semiconductors.