Mechanism and control of current transport in GaN and AlGaN Schottky barriers for chemical sensor applications
Mechanism and control of current transport in GaN and AlGaN Schottky barriers for chemical sensor applications
复制标题
DOI：
10.1016/j.apsusc.2007.10.101
复制
发表时间：
2008-04-15
影响因子：
6.7
通讯作者：
Akazawa, Masamichi
中科院分区：
文献类型：
--
作者：
Hasegawa, Hideki;Akazawa, Masamichi
近年来，人们对集成化高性能化学传感器芯片的开发产生了浓厚的兴趣。本文从化学传感器应用的角度讨论了GaN和AlGaN肖特基二极管中电流输运的理解和控制的现状。为此目的，除了一般性讨论外，还回顾了我们小组最近进行的一系列工作。首先，讨论了GaN和AlGaN肖特基势垒中的电流输运，引入薄表面势垒（TSB）模型来解释异常大的漏电流。在此之后，试图减少泄漏电流的介绍和讨论。然后，作为一个例子，气相传感器使用肖特基势垒，Pd/AlGaN/GaN肖特基二极管氢传感器最近由我们的小组提出的敏感机制和相关的电流传输进行了讨论。另一方面，在液相传感器中，液体与半导体之间的接触被电化学家认为是一种肖特基势垒。作为液相传感器的一种，介绍了本课题组最近研制的开栅AlGaN/GaN异质结场效应晶体管（HFET）pH传感器。最后，对全文进行了总结，并对今后的研究提出了一些建议. (C)2007 Elsevier B. V.保留所有权利。
Strong interests are recently emerging for development of integrated high-performance chemical sensor chips. In this paper, the present status of understanding and controlling the current transport in the GaN and AlGaN Schottky diodes is discussed from the viewpoint of chemical sensor applications. For this purpose, a series of works recently carried out by our group are reviewed in addition to a general discussion. First, current transport in GaN and AlGaN Schottky barriers is discussed, introducing the thin surface barrier (TSB) model to explain the anomalously large leakage currents. Following this, attempts to reduce the leakage currents are presented and discussed. Then, as an example of gas-phase sensors using Schottky barriers, a Pd/AlGaN/GaN Schottky diode hydrogen sensor developed recently by our group is presented with a discussion on the sensing mechanism and related current transport. On the other hand, in liquid-phase sensors, contact is made between liquid and semiconductor which is regarded as a kind of Schottky barrier by electrochemists. As one of such liquid-phase sensors, open-gate AlGaN/GaN heterostructure field effect transistor (HFET) pH sensor developed recently by our group is presented. Finally, a brief summary is given together with some remarks for future research. (C) 2007 Elsevier B.V. All rights reserved.