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采用X射线衍射技术、电子背散射衍射技术和扫描电镜分别观察了不同甲烷浓度条件下沉积的CVD自支撑金刚石薄膜的宏观织构、晶界分布和表面形貌.研究了一阶孪晶在金刚石晶体{111}面生长的原子堆垛过程.结果表明,由于一阶孪晶〈111〉60°的取向差关系以及{111}面的原子堆垛结构,使{111}面上容易借助碳原子的偏转沉积产生一阶孪晶.低甲烷浓度时,碳原子倾向于在表面能较低的{111}面沉积,为孪晶的形成提供了便利,且高频率孪晶使薄膜织构强度减弱.甲烷浓度升高使生长激活能较小的{001}面成为主要前沿生长面,因而只有〈001〉晶向平行薄膜法向的晶粒能够不断长大,因此孪晶形核概率明显减小.另外,在薄膜中发现二阶孪晶,并对二阶孪晶的形成进行了分析.
The macro-texture, grain boundary distribution and surface morphology of CVD self-supporting diamond films deposited under different methane concentrations were observed by X-ray diffraction, electron backscatter diffraction and scanning electron microscopy, respectively. The effects of first- Crystal {111} plane.The results show that the {111} plane can be easily crystallized by carbon atoms due to the orientation difference of first-order twins <111> 60 ° and the atomic stacking structure of {111} The first order twins are produced by the deflection deposition.The carbon atoms tend to deposit on the lower {111} plane with lower surface energy, which facilitates the formation of twins, and the high frequency twins weaken the texture strength of the film The higher concentration of methane makes the {001} plane, which has smaller growth activation energy, as the main front growth plane, and only the grains with <001> orientation parallel to the parallel film can grow continuously, so the twin nucleation probability decreases obviously. In addition, second-order twins were found in the films and the formation of second-order twins was analyzed.