共掺杂n型CVD金刚石薄膜的结构和性能

利用微波等离子体化学气相沉积(MPCVD)技术制备硫掺杂及硼/硫共掺杂n型金刚石薄膜,探讨n型CVD金刚石薄膜的特性和共掺杂机理.研究结果显示:随着单一硫(S)掺杂含量的增加,金刚石薄膜导电激活能降低,薄膜生长速率减小,薄膜中非金刚石结构相增多;硼/硫(B-S)共掺杂有利于增加硫在金刚石中的固溶度,提高硫在金刚石晶体中的掺杂率,降低金刚石薄膜的导电激活能(在0.26～0.33eV);与单一S掺杂相比较,B-S共掺杂金刚石薄膜生长速率低,薄膜质量和晶格完整性好;霍耳效应测试表明硫掺杂和硼/硫共掺杂金刚石薄膜具有n型导电特征,载流子浓度在1016-1018/cm3之间,载流子迁移率在7～80cm2V-1s-1之间.采用B-S共掺杂技术有利于提高CVD金刚石薄膜的晶格完整性,使得B-S共掺杂金刚石薄膜具有更高的载流子迁移率.

Structural characterization and properties of co-doping n-type CVD diamond films

Diamond films had been grown by microwave plasma assisted CVD using acetone as C source diluted in hydrogen with co -doping by using dimethyl disulfide and boron trioxide. The growth rate and resistivity of deposited films were all reduced with increasing sulfur additions. Under the same levels of S additions, conductive activation energy of films were decreased with the increasing of B additions, which were between 0. 26 - 0. 33eV. It is proved that the limited amounts of boron facilitated sulfur incorporation into diamond. The B - S co - doped diamond films were much more perfectl with higher quality than the S -doped diamond film. Hall effect measurements revealed that the S and B/S doped diamond films exhibited n - type, which carrier concentration and Hall mobility were among - 10^16 - 10^18/cm^3, 7 80cm2V^-1s^- 1 respectively. Compared with S- doping diamond film, B/S co- doping diamond film had higher Hall mobility.