藉由微波電漿束化學氣相沈積法可任意控制鑽石晶型方向性之研究

A Study of Growing Diamond Films with Controlled Orientation by Microwave Plasma Jet CVD System

楊豐榮(Fong-Rong Yang)

指導教授 ： 林啟瑞 ； 蘇春熺

國立臺北科技大學/機電學院/機電整合研究所/碩士(2008年)

摘要

在過去幾年來利用化學氣相沈積法成長鑽石一直廣泛的被人們所使用，而鑽石膜它的優良的機械性質與光電性質經常是用來作為感測器、微機電與半導體的重要元件之一，主要是由於鑽石具有硬度高、熱傳導度佳、傳聲速度快、彈性模數高、負電子親合力、低摩擦係數、高折射率、化學安定性和遠紅外光至X-ray範圍的光學穿透性等優異性質，其中鑽石的光電性質一直是人們主要利用的方向，鑽石的高靈敏度，耐高溫環境對於電子元件來說是很重要的一環。
然而鑽石擁有許多不同的晶體結構，而其中以（100）晶面的鑽石微結構品質最為良好，主要是（100）晶面結構的鑽石膜與（111）晶面結構的鑽石膜或非方向性鑽石相比，具有較少的成長缺陷、較好的鑽石晶粒品質、較大的鑽石晶粒尺寸、較平滑的表面形貌、高熱傳導率與緊密的連續性膜，所以方向性鑽石膜與雜亂無規則方向的鑽石膜相比擁有較好的機械性質與品質特性。
本研究主要是利用微波電漿束化學氣相沈積法成長高方向性鑽石膜，藉由通入不同的氣體系統（氫氣+甲烷、氫氣+甲烷+氧氣+氬氣），在n-type(100)的矽基板上成長（100）晶面之鑽石膜結構，此外藉由調整微波功率、工作壓力與甲烷濃度等實驗參數可以成長出高方向性之鑽石膜，以及觀察分析成長的高方向性鑽石薄膜的表面形貌以及品質特性。

關鍵字

控制晶型 ； 方向性鑽石膜 ； 微波電漿束化學氣相沈積法

並列摘要

Resent years the interest in growing diamond using CVD method arises mainly due to its enormous potentials of material property and photoconductivity for numerous applications. For example the transparency of diamond to a wide range of electromagnetic spectrum makes it an ideal material for producing IR windows and optical coatings. One of the most important features of oriented diamond films are good dark I-V characteristics, C-f characteristics and photocurrent under steady-state X-ray excitation investigated at room temperature.
The as-obtained (100)-oriented diamond films have lower concentrations of point and extended defects, thus are shown to possess better crystal quality than (111)-oriented or randomly oriented diamond films. The flat surfaces of (100)-oriented diamond films with closely-packed grains are smoother than those of (111)-oriented films.(100)-oriented thick diamond films with large grain size have higher thermal conductivity and crystal structures like nature diamonds.
These uniformly (100)-oriented diamond films were prepared by microwave plasma jet chemical vapor deposition (MPJCVD) from gaseous mixtures of CH4-H2 system and CH4-H2-Ar-O2 system. In order to grow (100)-oriented diamond films on n-type (100) silicon substrates, it is necessary to control concentrations of methane, oxygen and argon in a plasma atmosphere and to control substrate temperature by adjusting microwave power and chamber pressure.

並列關鍵字

controll diamond shape ； (100)-oriented ； microwave plasma jet chemical vapor deposition

參考文獻

[2] Isberg, J. et al.“High carrier mobility in single-crystal plasma-deposited diamond.”, Science, vol 297, 2002, pp.1670–1672.

[3] Qingfeng Su,”Influence of texture on optical and electrical properties of diamond films” ,Vacuum ,81 ,2007, pp.644–648.

[4] Mariko Suzuki,” Electrical properties of B-related acceptor in B-doped homoepitaxial diamond layers grown by microwave plasma CVD”, Diam. . Relat. Mater., vol.13, 2004, pp.198-202.

[5] A. Secroun,” Photoconductive properties of lightly N-doped single crystal

CVD diamond films”, Diam. Relat. Mater., vol.16, 2007, pp.953-957.