Owing to its exceptional physical and electronic properties, gallium nitride (GaN) is a promising material that can find application in the fields of high-power and high-frequency electronics. However, there are still several hurdles in GaN technology, which hinder the full exploitation of the great potential of this material. For that reason the scientific community working on GaN-based materials is continuously involved in addressing a variety of physical and technological problems encountered in the fabrication of GaN devices. This paper aims to give an overview on some selected scientific problems related to GaN technology for power electronics devices, with a special attention to the case of high electron mobility transistors (HEMTs). In particular, after an introduction on the fundamental physical properties of the material, special emphasis is given to the problem of current transport at metal/GaN interfaces, considering both Ohmic and Schottky contacts. Afterwards, the importance of dielectrics either as passivation or gate insulation layers is briefly highlighted. Then, the possible approaches to control the two-dimensional electron gas (2DEG) in AlGaN/GaN heterostructures and to fabricate normally-OFF HEMTs are presented. Finally, a short description of the status of vertical GaN devices technology is given.

中文翻译：

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电力电子氮化镓材料的物理与技术

由于其出色的物理和电子性能，氮化镓（GaN）是一种有前途的材料，可以在高功率和高频电子领域中找到应用。但是，GaN技术仍然存在一些障碍，这阻碍了这种材料的巨大潜力的充分利用。因此，致力于GaN基材料的科学界不断参与解决GaN器件制造过程中遇到的各种物理和技术问题。本文旨在概述与电力电子设备GaN技术相关的一些选定的科学问题，并特别关注高电子迁移率晶体管（HEMT）的情况。特别是在介绍了材料的基本物理特性之后，考虑到欧姆和肖特基接触，特别强调了金属/ GaN界面上的电流传输问题。之后，简要强调了电介质作为钝化层或栅极绝缘层的重要性。然后，提出了可能的方法来控制AlGaN / GaN异质结构中的二维电子气（2DEG）并制造常关型HEMT。最后，简要介绍了垂直GaN器件技术的现状。提出了控制AlGaN / GaN异质结构中的二维电子气（2DEG）和制造常关型HEMT的可能方法。最后，简要介绍了垂直GaN器件技术的现状。提出了控制AlGaN / GaN异质结构中的二维电子气（2DEG）和制造常关型HEMT的可能方法。最后，简要介绍了垂直GaN器件技术的现状。