Capacitance pressure sensor based on GaN high-electron-mobility transistor-on-Si membrane
Capacitance pressure sensor based on GaN high-electron-mobility transistor-on-Si membrane
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DOI：
10.1063/1.1920433
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发表时间：
2005-06-20
影响因子：
4
通讯作者：
Pearton, SJ
中科院分区：
文献类型：
--
作者：
Kang, BS;Kim, J;Pearton, SJ
发现具有和不具有Au栅极的AlGaN/GaN高电子迁移率晶体管（HEMT）在将栅极区域暴露于各种卤素离子时表现出沟道电导的显著变化。卤化物离子的极性性质导致HEMT上的栅极区域中的表面电荷的变化，从而在半导体/液体界面处产生表面电势的变化。与无栅HEMT相比，具有Au栅电极的HEMT不仅使改变沟道电导的灵敏度加倍，而且还显示出相反的电导行为。当阴离子吸附在Au上时，它们产生一个与电价有关的反电荷。这些阴离子从本体溶液中拖出一些抗衡离子，或者在金属上产生图像正电荷以获得所需的中性。通过在Au表面上共价键合卤化物官能团的适当修饰，无栅HEMT可以用作一系列化学品的传感器。这为广泛的集成生物、化学和流体监测传感器的表面功能化创造了许多可能性。(c)在通过环境压力的变化施加拉伸和压缩应变期间，测量了在Si衬底上制造的AlGaN/GaN高电子迁移率晶体管（HEMT）膜结构的沟道电容的变化。在+9.5 bar的固定压力下，通道的电容显示出7.19 +/-0.45 × 10（-3）pF/μ m m m的变化，作为膜半径的函数，并且对于600 m m半径的膜，在-0.5和+1 bar之间显示出线性特征响应，灵敏度为0.86 pF/bar。在线性范围内滞后为0.4%。这些AlGaN/GaN HEMT膜为基础的传感器似乎是有前途的室温和高温压力传感应用。(c)2005年美国物理学会。
AlGaN/GaN high electron mobility transistors (HEMTs) both with and without a Au gate are found to exhibit significant changes in channel conductance upon exposing the gate region to various halide ions. The polar nature of the halide ions leads to a change of surface charge in the gate region on the HEMT, producing a change in the surface potential at the semiconductor/liquid interface. HEMTs with a Au-gate electrode not only doubled the sensitivity of changing the channel conductance as compared to gateless HEMT, but also showed the opposite conductance behavior. When anions adsorbed on the Au, they produced a counter charge for electrovalence. These anions drag some counter ions from the bulk solution or create an image positive charge on the metal for the required neutrality. The gateless HEMTs can be used as sensors for a range of chemicals through appropriate modification with covalently bonded halide functional groups on the Au surface. This creates many possibilities to functionalize the surface for a wide range of integrated biological, chemical, and fluid monitoring sensors. (c) 2005 American Institute of Physics.The changes in the capacitance of the channel of an AlGaN/GaN high-electron-mobility transistor (HEMT) membrane structure fabricated on a Si substrate were measured during the application of both tensile and compressive strain through changes in the ambient pressure. The capacitance of the channel displays a change of 7.19 +/- 0.45 x 10(-3) pF/mu m m as a function of the radius of the membrane at a fixed pressure of + 9.5 bar and exhibits a linear characteristic response between -0.5 and + 1 bar with a sensitivity of 0.86 pF/bar for a 600 m m radius membrane. The hysteresis was 0.4% in the linear range. These AlGaN/GaN HEMT membrane-based sensors appear to be promising for both room-temperature and elevated-temperature pressure-sensing applications. (c) 2005 American Institute of Physics.