Electrical and Structural Properties of In-Situ MOCVD Grown Al$_2$O$_3$/$β$-Ga$_2$O$_3$ and Al$_2$O$_3$/$β$-(Al$_x$Ga$_{1-x}$)$_2$O$_3$ MOSCAPs

A F M Anhar Uddin Bhuiyan; Lingyu Meng; Dong Su Yu; Sushovan Dhara; Hsien-Lien Huang; Vijay Gopal Thirupakuzi Vangipuram; Jinwoo Hwang; Siddharth Rajan; Hongping Zhao

doi:10.1063/5.0256525

paper

Electrical and Structural Properties of In-Situ MOCVD Grown Al $_{2}$ O $_{3}$ / $β$ -Ga $_{2}$ O $_{3}$ and Al $_{2}$ O $_{3}$ / $β$ -(Al $_{x}$ Ga $_{1 - x}$ ) $_{2}$ O $_{3}$ MOSCAPs

arXiv:2501.10628 · doi:10.1063/5.0256525

Abstract

This study investigates the electrical and structural properties of MOSCAPs with in-situ MOCVD-grown Al $_{2}$ O $_{3}$ dielectrics on (010) $β$ -Ga $_{2}$ O $_{3}$ and $β$ -(Al $_{x}$ Ga $_{1 - x}$ ) $_{2}$ O $_{3}$ films. The Al $_{2}$ O $_{3}$ / $β$ -Ga $_{2}$ O $_{3}$ MOSCAPs showed a strong dependence on Al $_{2}$ O $_{3}$ deposition temperature. At 900 $^{\circ}$ C, reduced voltage hysteresis ( $\sim$ 0.3 V) and improved reverse breakdown voltage (74.5 V) were observed, with breakdown fields of 5.01 MV/cm in Al $_{2}$ O $_{3}$ and 4.11 MV/cm in $β$ -Ga $_{2}$ O $_{3}$ . At 650 $^{\circ}$ C, higher hysteresis ( $\sim$ 3.44 V) and lower reverse breakdown voltage (38.8 V) were observed, with breakdown fields of 3.69 MV/cm in Al $_{2}$ O $_{3}$ and 2.87 MV/cm in $β$ -Ga $_{2}$ O $_{3}$ . However, forward breakdown fields improved from 5.62 MV/cm (900 $^{\circ}$ C) to 7.25 MV/cm (650 $^{\circ}$ C). STEM revealed improved crystallinity and sharper interfaces at 900 $^{\circ}$ C, enhancing reverse breakdown performance. For Al $_{2}$ O $_{3}$ / $β$ -(Al $_{x}$ Ga $_{1 - x}$ ) $_{2}$ O $_{3}$ MOSCAPs, increasing Al composition ( $x$ = 5.5\% to 9.2\%) reduced carrier concentration and improved reverse breakdown fields from 2.55 to 2.90 MV/cm in $β$ -(Al $_{x}$ Ga $_{1 - x}$ ) $_{2}$ O $_{3}$ and 2.41 to 3.13 MV/cm in Al $_{2}$ O $_{3}$ . Forward breakdown fields in Al $_{2}$ O $_{3}$ improved from 5.0 to 5.4 MV/cm as Al composition increased. STEM confirmed compositional homogeneity and excellent stoichiometry of Al $_{2}$ O $_{3}$ and $β$ -(Al $_{x}$ Ga $_{1 - x}$ ) $_{2}$ O $_{3}$ layers. These findings highlight the robust electrical performance, high breakdown fields, and structural quality of Al $_{2}$ O $_{3}$ / $β$ -Ga $_{2}$ O $_{3}$ and Al $_{2}$ O $_{3}$ / $β$ -(Al $_{x}$ Ga $_{1 - x}$ ) $_{2}$ O $_{3}$ MOSCAPs for high-power applications.

Electrical and Structural Properties of In-Situ MOCVD Grown Al2​O3​/β-Ga2​O3​ and Al2​O3​/β-(Alx​Ga1−x​)2​O3​ MOSCAPs

Abstract

References in corpus (3)

Electrical and Structural Properties of In-Situ MOCVD Grown Al $_{2}$ O $_{3}$ / $β$ -Ga $_{2}$ O $_{3}$ and Al $_{2}$ O $_{3}$ / $β$ -(Al $_{x}$ Ga $_{1 - x}$ ) $_{2}$ O $_{3}$ MOSCAPs