重离子注入GaAs辐照损伤研究

Irradiation Damage of GaAs Induced by Kr Ion

利用4.5 MeV的氪离子(Kr^(17+))辐照(100)晶向本征未掺杂和高掺锌(P型)、(100)和(110)混合晶向的高掺硅(N型)砷化镓(GaAs)半导体材料,辐照注量为1×10^(12)～3×10^(14)cm^(-2),测试辐照后材料的拉曼光谱。随着辐照注量增大,材料的纵向光学(longitudinal optical,LO)声子峰向低频方向移动,出现了明显的非对称展宽,并且N型样品辐照后,晶体结构损伤要大于P型与本征未掺杂样品。3种类型样品的LO峰频移随辐照损伤的变化趋势一致,研究表明,掺杂元素不影响材料本身的晶体结构,可能是因为混合晶向的生长方式导致辐照后N型GaAs结构稳定性变差。

Semi-insulting and Silicon-doping （ N-type） GaAs （100） and Zinc-doping （P-type） GaAs（110 and 100） were irradiated by 4. 5 MeV Kr^7＋ ions with fluences ranging from 1×10^12～3×10^14cm^-2. As the ion fluence increases, the longitudinal-optical （LO） phonon peak moves to the low-frequency, and there is an obvious asymmetric broadening. The crys-talline structure damage of N-type sample after irradiation is more serious than those of P- type and the semi-insulting samples. The frequency shift of LO phonon peak in three types of samples is consistent with the irradiation damage, which shows that doping elements will not affect the crystalline structure of the material itself. It may be proved that the mixed crystal growth mode results in unstability of N-type GaAs after irradiation.