Ga 2 O 3 Based Heterostructure FETs
(HFETs) for Microwave
and Millimeter-Wave Applications
R. Singh, T. R. Lenka, D. Panda, R. T. Velpula, B. Jain, H. Q. T. Bui,
and H. P. T. Nguyen
Abstract The rapid development of the power electronic devices over the last few
decades to cater demands of ever increasing wireless communication technologies,
traditional as well as new military applications, and many more, have been further
fueled by work-from-home (WFH) due to unprecedented global pandemic COVID19. These high frequencies and high-power applications have necessitated the introduction and development of wide bandgap semiconductors over the period because
of their suitable material properties. However, these wide bandgap materials, such
as silicon carbide (SiC) and gallium nitride (GaN), based device technologies have
already extended their cycle of development and optimization due to various reasons.
Moreover, still facing critical challenges like producing large-size, cost-effective, and
high-quality substrates. In the quest of better material properties suitable for highvoltage and high-frequency applications, a new ultra-wide bandgap (UWB) semiconductor material gallium oxide (Ga 2 O 3 ), although studied and reported way back
in mid of twentieth century, has attracted research community only in last few years
as a supplement to existing silicon carbide (SiC) and gallium nitride (GaN) technologies. Ga 2 O 3 is an ultra-wide bandgap (UWB) semiconductor having different
crystal structures with energy bandgap values up to 5.3 eV, and bulk crystals can be
grown using melt-growth techniques which facilitate the availability of large-size,
cost-effective, single-crystal substrates. Gallium oxide crystallizes into five different
structures: monoclinic, rhombohedral, defective spinel, cubic, and orthorhombic
structures, and represented as β-, α-, γ-, δ-, and ε-Ga 2 O 3, respectively. Among these
R. Singh · T. R. Lenka (B)
Department of Electronics and Communication Engineering, National Institute of Technology
Silchar, Silchar, Assam 788010, India
e-mail: trlenka@ieee.org
R. Singh
e-mail: rajan_singh@ieee.org
D. Panda
School of Electronics, VIT-AP University, Amaravati, Andhra Pradesh 522237, India
R. T. Velpula · B. Jain · H. Q. T. Bui · H. P. T. Nguyen
Department of Electrical and Computer Engineering, New Jersey Institute of Technology,
Newark, New Jersey 07102, USA
© The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2021
A. Biswas et al. (eds.), Emerging Trends in Terahertz Engineering and System
Technologies, https://doi.org/10.1007/978-981-15-9766-4_11
209
(HFETs) for Microwave
and Millimeter-Wave Applications
R. Singh, T. R. Lenka, D. Panda, R. T. Velpula, B. Jain, H. Q. T. Bui,
and H. P. T. Nguyen
Abstract The rapid development of the power electronic devices over the last few
decades to cater demands of ever increasing wireless communication technologies,
traditional as well as new military applications, and many more, have been further
fueled by work-from-home (WFH) due to unprecedented global pandemic COVID19. These high frequencies and high-power applications have necessitated the introduction and development of wide bandgap semiconductors over the period because
of their suitable material properties. However, these wide bandgap materials, such
as silicon carbide (SiC) and gallium nitride (GaN), based device technologies have
already extended their cycle of development and optimization due to various reasons.
Moreover, still facing critical challenges like producing large-size, cost-effective, and
high-quality substrates. In the quest of better material properties suitable for highvoltage and high-frequency applications, a new ultra-wide bandgap (UWB) semiconductor material gallium oxide (Ga 2 O 3 ), although studied and reported way back
in mid of twentieth century, has attracted research community only in last few years
as a supplement to existing silicon carbide (SiC) and gallium nitride (GaN) technologies. Ga 2 O 3 is an ultra-wide bandgap (UWB) semiconductor having different
crystal structures with energy bandgap values up to 5.3 eV, and bulk crystals can be
grown using melt-growth techniques which facilitate the availability of large-size,
cost-effective, single-crystal substrates. Gallium oxide crystallizes into five different
structures: monoclinic, rhombohedral, defective spinel, cubic, and orthorhombic
structures, and represented as β-, α-, γ-, δ-, and ε-Ga 2 O 3, respectively. Among these
R. Singh · T. R. Lenka (B)
Department of Electronics and Communication Engineering, National Institute of Technology
Silchar, Silchar, Assam 788010, India
e-mail: trlenka@ieee.org
R. Singh
e-mail: rajan_singh@ieee.org
D. Panda
School of Electronics, VIT-AP University, Amaravati, Andhra Pradesh 522237, India
R. T. Velpula · B. Jain · H. Q. T. Bui · H. P. T. Nguyen
Department of Electrical and Computer Engineering, New Jersey Institute of Technology,
Newark, New Jersey 07102, USA
© The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2021
A. Biswas et al. (eds.), Emerging Trends in Terahertz Engineering and System
Technologies, https://doi.org/10.1007/978-981-15-9766-4_11
209