直流喷射电弧等离子体制备金刚石单晶的研究

通过利用光发射谱技术,探测了大功率直流喷射电弧等离子体增强化学气相沉积方法中沉积区域的气相激元分布,进而优选了金刚石生长的位置.在沉积过程中,不断使衬底做背向等离子体的运动,实现了大颗粒金刚石的连续生长,颗粒尺寸达到约1 mm3.采用劳厄背反射X射线衍射测试技术和拉曼谱技术,对所制备的样品进行了测试,结果表明:所制备的颗粒为金刚石单晶.对于大尺寸衬底,研究了背向运动速度对沉积晶体的形貌和质量的影响,发现了ATG型不稳定形貌.

Growth of Diamond Single Crystal by DC Arcjet Plasma Enhanced Chemical Vapor Deposition

Optical emission spectra(OES) technique was employed to diagnose the gas phase in DC Arcjet plasma.Based on the OES result and deposition result on the cover plate,the growth position was optimized to prepare for the growth of the diamond single crystal.The large grain,up to one cubic millimeter,was grown by continuously descending the substrate.The as-grown grain was characterized by the Laue back reflected X-ray diffraction,Raman spectra and scanning electron microscope(SEM).The results indicated that the as-grown grain was diamond single crystal.The further experimental results showed that unsuit descending velocity might result in ATG type morphology instability on the growth surface,which would cause the crack of the grain and polycrystalization.