自支撑硼掺杂金刚石膜残余应力和微观应力的XRD分析

Analysis of residual stress and micro-stress in free-standing boron-doped polycrystalline diamond films by XRD

利用XRD(包括sin^2ψ法)研究了电子辅助热灯丝化学气相沉积法(EA-HFCVD)生长的自支撑硼掺杂多晶金刚石薄膜的残余应力和微观应力。结果表明,薄膜的残余应力为压应力,随着薄膜制备过程中硼流量的增加,应力值有减小的趋势。薄膜的微观应力随着硼流量的增加,由拉应力转变为压应力然后又转变为拉应力。残余应力和微观应力的变化归因于一定量的硼掺杂导致的多晶膜中晶粒尺寸、晶面取向及孪晶变化的共同作用。

The residual stress and micro-stress in free-standing boron-doped polycrystalline diamond films, grown by an electron-assisted hot filament chemical vapor deposition （EA-HFCVD） were analyzed by X-ray diffraction （XRD） including sin^2ψ method. The results show that the residual stress is compressive, With increasing boron flow rate, the stress is gradually decreased. The micro-stress varies as tensile-→compressive→tensile in the films fabricated with increasing boron flow rate in the growth processes. The variations in the residual stress and micro-stress as a function of boron doping level are strongly dependent on the grain size, growth orientation, and appearance of twins in the boron-doped diamond films.