Investigation of the effect of hydrogen on electrical and optical properties in chemical vapor deposited on homoepitaxial diamond films
Investigation of the effect of hydrogen on electrical and optical properties in chemical vapor deposited on homoepitaxial diamond films
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DOI：
10.1063/1.364299
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发表时间：
1997-01-15
影响因子：
3.2
通讯作者：
Kajimura, K
中科院分区：
文献类型：
--
作者：
Hayashi, K;Yamanaka, S;Kajimura, K
本文研究了化学气相沉积法制备的未掺杂和掺硼金刚石薄膜中高电导层的电学和光学性质。发现在297 K下，氢化的未掺杂和掺硼金刚石薄膜都具有接近10（18）cm（-3）的高浓度空穴。这些膜表现出很小的温度依赖性的空穴浓度之间的120和400 K，而氧化的B掺杂的膜具有很强的温度依赖性与活化能为0.38 eV。在297 K下，所有氢化膜的霍尔迁移率都接近30 cm（2）/Vs，比氧化的掺B膜小一到两个数量级，并且随着温度的升高而增加。氢化未掺杂膜的Al肖特基接触的I-V特性显示出优异的整流特性，并且它们的正向特性的温度依赖性很好地由包括隧穿过程的结理论（即，场致发射理论）解释，表明耗尽层由于耗尽层中的高密度空间电荷而变薄。我们还发现了一个广泛的阴极射线发光峰在540 nm左右的氢化薄膜，随后的氧化处理消失，表明存在氢相关的间隙状态的沉积同质外延金刚石薄膜的次表面区域。用二次离子质谱仪在氢化膜的次表面区域检测到高密度的氢。这些实验结果表明，氢诱导的浅受体在沉积（氢化）金刚石薄膜的表面区域中的存在，并且在电学和光学性质中观察到的氢化和氧化膜之间的差异源于在次表面区域中掺入的氢。(C)1997年美国物理学会。
We have investigated electrical and optical properties of the high-conductivity layers formed in both undoped and B-doped diamond films prepared by chemical vapor deposition, It is found that both hydrogenated undoped and B-doped diamond films have high-concentration holes of similar to 10(18) cm(-3) at 297 K. These films exhibit little temperature dependence of the hole concentration between 120 and 400 K, while that of the oxidized B-doped film has a strong temperature dependence with an activation energy 0.38 eV. The Hall mobility of all the hydrogenated films of similar to 30 cm(2)/Vs at 297 K is one to two orders of magnitude smaller than that of the oxidized B-doped film and increases with increasing temperature. The I-V characteristics of Al-Schottky contacts to the hydrogenated undoped film show excellent rectification properties and the temperature dependence of their forward characteristics is well explained by a junction theory inclusive of the tunneling process, i.e. thermionic-field emission theory, indicating that the depletion layer becomes thin due to high-density space charge in the depletion layer. We have also found a broad cathodoluminescence peak at around 540 nm in the hydrogenated films which disappears with subsequent oxidation treatment, indicating the existence of hydrogen-related gap states in the subsurface region of as-deposited homoepitaxial diamond films. High density hydrogen is detected in the subsurface region of the hydrogenated films by secondary ion mass spectrosccopy. These experimental results suggest the existence of hydrogen-induced shallow accepters in the surface region of as-deposited (hydrogenated) diamond films and that the difference between the hydrogenated and the oxidized films observed in both electrical and optical properties originates from hydrogen incorporated in the subsurface region. (C) 1997 American Institute of Physics.