Electron beam probing of non-equilibrium carrier dynamics in 18 MeV alpha particle- and 10 MeV proton-irradiated Si-doped β -Ga2O3 Schottky rectifiers

Abstract

Minority hole diffusion length and lifetime were measured in independent experiments by electron beam-induced current and time-resolved cathodoluminescence in Si-doped β-Ga2O3 Schottky rectifiers irradiated with 18 MeV alpha particles and 10 MeV protons. Both diffusion length and lifetime exhibited a decrease with increasing temperature. The non-equilibrium minority hole mobility was calculated from the independently measured diffusion length and lifetime, indicating that the so-called hole self-trapping is most likely irrelevant in the 77–295 K temperature range.

Variable temperature probing of minority carrier transport and optical properties in p-Ga2O3

“…26,27,29,[45][46][47][48] The self-localization of excitons occurs at O(I) and O(II) site, corresponding to UVL ′ and UVL bands, respectively. 47,49 Although, as has been shown from Electron Paramagnetic Resonance (EPR) measurements 50 and confirmed by several independent EBIC studies on n-type β-Ga 2 O 3 , [20][21][22][23]39,51,52 the self-localization of holes is unstable above 110 K, the optical signature of the self-trapped excitons persists in CL and photoluminescence (PL) measurements. Note that the relative contribution of UVL ′ and UVL bands in both A and B samples is much lower than in n-type β-Ga 2 O 3 , found in earlier reports.…”

“…The incorporation of doped layers in devices such as Schottky diodes and field-effect transistors (FETs), including metal-oxide-semiconductor FETs (MOSFETs), and their ability to withstand high energy particle radiation have been explored. [15][16][17][18][19][20][21][22][23][24] Replicating these results to achieve p-type conductivity in β-Ga 2 O 3 has proven very difficult due to factors such as doping asymmetry, high compensation of acceptors, the high ionization energy of acceptor levels, and hole-trapping at O(I) and O(II) sites. [25][26][27][28][29][30] Despite these difficulties, native p-type conductivity was demonstrated at high temperatures in undoped β-Ga 2 O 3 .…”

Radiation‐Tolerant Electronic Devices Using Wide Bandgap Semiconductors

“…Efforts to address these issues have been underway over the past two decades. Substantial progress has also been made in designing radiation‐hard thin films transistors (TFTs) with ZnO, Ga 2 O 3 , In 2 O 3 , SnO 2 , IGZO, SiC, GaN, and many other WBGs, [ 17–50 ] which are used in the CMOS integrated circuits (ICs) over a long period under various radiations. Emerging memory technologies were also developed to stabilize the data storage performance in high temperatures and extremely harsh environments.…”

“…The large, spherical nsorbitals in the conduction band (CB) of MOS also play a critical role in high dopability for hosting a high density of electrons, leading to the remarkably tolerance to various radiation fluences. [17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35] Understanding the apparent immunity of the WBGs to various radiation environments and radiation-hard electronic engineering would be critical for pushing the technology further and understanding its limitations. Efforts to address these issues have been underway over the past two decades.…”

Minority-carrier dynamics in β-gallium oxide probed by depth-resolved cathodoluminescence

“…There are a few direct techniques for observing carrier dynamics. Electron beam-induced current (EBIC) is a technique used to determine the minority carrier diffusion length [27][28][29][30][31][32][33]. The pump-probe technique, which is a timeresolved method, has been applied to β-Ga 2 O 3 [34,35], and the hole self-trapping coefficient was estimated to be 6.4 × 10 −8 cm 3 s −1 [35].…”