Materials issues and devices of α- and β-Ga2O3

Abstract

Ga2O3 is an ultrawide bandgap semiconductor with a bandgap energy of 4.5–5.3 eV (depending on its crystal structure), which is much greater than those of conventional wide bandgap semiconductors such as SiC and GaN (3.3 eV and 3.4 eV, respectively). Therefore, Ga2O3 is promising for future power device applications, and further high-performance is expected compared to those of SiC or GaN power devices, which are currently in the development stage for commercial use. Ga2O3 crystallizes into various structures. Among them, promising results have already been reported for the most stable β-Ga2O3, and for α-Ga2O3, which has the largest bandgap energy of 5.3 eV. In this article, we overview state-of-the-art technologies of β-Ga2O3 and α-Ga2O3 for future power device applications. We will give a perspective on the advantages and disadvantages of these two phases in the context of comparing the two most promising polymorphs, concerning material properties, bulk crystal growth, epitaxial growth, device fabrication, and resulting device performance.

A novel β‐Ga2O3 HEMT with fT of 166 GHz and X‐band POUT of 2.91 W/mm

“…are being commercially produced. 31 Defect density-dislocations in these β-Ga 2 O 3 crystals are found to be 10 3 cm −2 and can cause deterioration in device performance in the form of current leakage paths. 32 Out of various epitaxial growth techniques, PLD is preferred for depositing thin β-Ga 2 O 3 films mainly due to its low-temperature requirement.…”

Влияние влажности окружающей среды на электрическую проводимость полиморфных Ga-=SUB=-2-=/SUB=-O-=SUB=-3-=/SUB=--структур

“…Достигнут значительный прогресс в выращивании эпитаксиальных пленок [1][2][3][4][5][6][7][8][9]. Корундообразная α-фаза обладает среди всех политипов оксида галлия наибольшей шириной запрещенной зоны E g , не менее 5.3 эВ, и при легировании Sn или Si имеет высокую донорную проводимость [3,8,[10][11][12][13][14][15]. В то же время ε-фаза с E g , близкой к 4.9 эВ [1,2,16], является второй после β-Ga 2 O 3 по температурной стабильности.…”

“…Фаза ε-Ga 2 O 3 интересна тем, что обладает спонтанной поляризацией [2]. Оба указанных политипа оксида галлия уже сейчас опробованы для ряда применений [1,11,[17][18][19][20] в области электронных приборов и сенсоров.…”

Terahertz Emission Spectroscopy and Microscopy on Ultrawide Bandgap Semiconductor β-Ga2O3

“…Gallium oxide (Ga 2 O 3 ) is an attractive ultrawide-bandgap semiconductor for the use in a variety of applications such as gas sensors, high-power electronics, and deep-ultraviolet (UV) photo-detectors [1][2][3]. In recent years, tremendous efforts have been made to improve material quality and device performance.…”