Influence of fast neutrons on electrical properties in neutron transmutation doped GaAs: New annealing stage

Abstract

In neutron transmutation doping (NTD) to the undoped semi-insulating GaAs, a new annealing stage related to the tunneling assisted hopping conduction was found around 400 °C for fast neutron fluences of ≥7.0×1017 n/cm2. It is suggested that this stage is based on the enhancement in the hopping conduction by the activated dopant in the NTD process. The stage was not observed for the irradiation with a small amount of fast neutrons. The activation energy for the annihilation of As antisite defects (AsGa) was found to be 0.9 eV. The annealing temperature to achieve the desired carried concentration increased with the fast neutron fluence.

Fabrication of uniform Ge-nanocrystals embedded in amorphous SiO2 films using Ge-ion implantation and neutron irradiation methods

“…8 Several attempts have been made recently to improve the uniformity of QD distribution. Neutron transmutation doping ͑NTD͒ is a technique which utilizes the nuclear reaction of thermal neutrons with the isotopes in a semiconductor material, [15][16][17] and it has been reported that impurities are distributed homogeneously in a material [18][19][20][21][22] by using NTD. Achieving uniform QDs under the 3D confinement conditions remains one of the most daunting challenges ͑in quantum-dot formation, etc͒.…”

Effect of annealing and hydrogenation on neutron-transmutation-doped GaAs

“…The method has several advantages in comparison with other doping methods: The method can dope the impurities uniformly, control the impurity concentration accurately, and activate the carriers by relatively low-temperature thermal treatment [4, 51. After Mirianashvili and Nanobashivili [6] introduced doping in GaAs using the NTD method, many groups used the NTD method in compound semiconductors for device applications [7]. When neutrons are introduced into a semiconductor, the doped semiconductor foms defect levels, and the levels restrict the activation of injected impurities.…”