摘要
以Ib型(100)取向高温高压(HPHT)单晶金刚石为基底、H2-CH4-CO2混合气为反应气源,利用10kW、2.45GHz不锈钢谐振腔式微波等离子体化学气相沉积(MPCVD)装置进行金刚石同质外延生长。通过光学显微镜表征外延生长金刚石的表面形貌;Raman光谱表征金刚石的结晶质量;螺旋测微仪测厚再计算生长速率,着重探讨工艺因素中氧碳比对同质外延金刚石生长速率、表面形貌、金刚石结晶质量的影响。结果表明随着氧碳比的增加,金刚石生长模式由二维形核模式转变为台阶流模式,结晶质量提高,生长速率变慢;在微波功率7.8kW、CH4浓度(与H2的比例)8%、气压18kPa、基底温度1080℃条件下,氧碳比为0.8时,金刚石结晶质量好且生长速率高(达16μm/h)。反应气源中引入合适比例的CO2是获得高的生长速率同时有效改善同质外延单晶金刚石结晶质量的有效方法。
Monocrystal homoepitaxial diamond has been grown on type Ib HPHT diamond（100） substrates using a 10kW,2.45GHz stainless steel resonant cavity microwave plasma chemical vapor deposition（MPCVD） system with H2-CH4-CO2 as source gases.The effect of oxygen-carbon ratio on growth rate,morphology and crystallinity was investigated for the homoepitaxial diamond.The as-grown diamonds have been characterized using optical microscope,Raman spectroscopies and propeller micrometer.The results indicated that with the increasing of oxygen-carbon ratio,the diamond growth mode changes from two-dimension nucleation mode to step-flow mode and the crystalline quality has been obviously improved while the growth rate substantially decreases.The optimized oxygen-carbon ratio was verified to be 0.8 for diamond homoepitaxial growth when microwave power is 7.8kW,methane-hydrogen ratio is 8%,gas pressure is 18kPa and substrate temperatue was 1080℃,and the growth rate can reach 16μm/h.The addition of a proportional of CO2 into H2-CH4 gas phase system was an available way to improve crystallinity of the homoepitaxial diamond and to get relatively high growth rate.
出处
《功能材料》
EI
CAS
CSCD
北大核心
2013年第14期2065-2068,2073,共5页
Journal of Functional Materials
基金
国家自然科学基金资助项目(11205127)
碳纳米材料四川省青年科技创新研究团队专项资助项目(2011JTD0017)
