The Evolution of Manufacturing Technology for GaN Electronic Devices

Abstract

GaN has been widely used to develop devices for high-power and high-frequency applications owing to its higher breakdown voltage and high electron saturation velocity. The GaN HEMT radio frequency (RF) power amplifier is the first commercialized product which is fabricated using the conventional Au-based III–V device manufacturing process. In recent years, owing to the increased applications in power electronics, and expanded applications in RF and millimeter-wave (mmW) power amplifiers for 5G mobile communications, the development of high-volume production techniques derived from CMOS technology for GaN electronic devices has become highly demanded. In this article, we will review the history and principles of each unit process for conventional HEMT technology with Au-based metallization schemes, including epitaxy, ohmic contact, and Schottky metal gate technology. The evolution and status of CMOS-compatible Au-less process technology will then be described and discussed. In particular, novel process techniques such as regrown ohmic layers and metal–insulator–semiconductor (MIS) gates are illustrated. New enhancement-mode device technology based on the p-GaN gate is also reviewed. The vertical GaN device is a new direction of development for devices used in high-power applications, and we will also highlight the key features of such kind of device technology.

GaN Heterostructures as Innovative X-ray Imaging Sensors—Change of Paradigm

“…A listed historical summary can be found by Roccaforte and Leszczynski [10]. Binary AlN/GaN HEMTs are preferably grown by plasma-assisted molecular beam epitaxy (PA-MBE), as well as metal-organic chemical vapour deposition (MOCVD), which is also known as metal-organic chemical vapour phase epitaxy (MOCVPE) [11,12]. The latter method, which is likely to dominate by more than one magnitude, has gained increased attraction, since MOCVD offers simple fabrication of large quantities, as requested in commercial use for the production of complex semiconductor structures [13] (Figure 1).…”

Analytic solution of carrier concentration as an explicit function of gate voltage in AlGaN/GaN HEMTs using the Lambert W‐function

“…Good reviews of HEMTs have been presented 2,3 and this device has also been referred as modulation doped FET (MODFET), heterostructure FET (HFET), two‐dimensional electron gas FET (TEGFET), and selectively doped heterojunction transistor (SDHT). The first gallium arsenide (GaAs) HEMT was reported in 1979 while the first gallium nitride (GaN) HEMT was fabricated in 1993 and it went to production in 2006 in Japan 4 . GaN is a wide band‐gap semiconductor which offers interesting advantages such as high‐breakdown voltage, high‐saturation velocity and high‐electron mobility 1,2 5–7 .…”

“…The first gallium arsenide (GaAs) HEMT was reported in 1979 while the first gallium nitride (GaN) HEMT was fabricated in 1993 and it went to production in 2006 in Japan. 4 GaN is a wide band-gap semiconductor which offers interesting advantages such as highbreakdown voltage, high-saturation velocity and high-electron mobility. 1,2 5-7 As a result of the previous considerations, GaN HEMTs are now the dominant devices for high-power high-frequency applications.…”

“…2,8 There are three main approaches to model semiconductor devices: rigorous physical models, empirical models and approximate circuit models. [2][3][4]6,9,10 The rigorous physical models require intensive numerical calculations and they are usually implemented in technology computer-aided design (TCAD) tools. The empirical or behavioral models are easy to implement but they are not physics based.…”

Multitemperature Modeling of Thermal Transport across a Au–GaN Interface from Ab Initio Calculations

“…Ubiquitous in integrated circuits, metal–nonmetal interfaces, such as Au–GaN interfaces, − are often identified as bottlenecks for the performance of devices with the heat dissipation abilities playing an important role. − With device dimensions shrinking toward nanoscale sizes, an accurate understanding and modeling of the energy transfer mechanisms at such interfaces is highly desirable. The thermal energy flow is complex due to the mismatch (e.g., energy and momentum) between the electrons, which are the major thermal energy carriers on the metal side, and the lattice vibrations or phonons on the nonmetal side.…”