A study of surface states in Ar plasma exposed InP measured by photoreflectance

Ar 플라즈마가 조사된 InP의 Photoreflectance 방법에 의한 표면상태 연구

The surface state of Ar plasma-exposed Fe doped SI-InP have been investigated by photoreflectance (PR). From Ar plasma-exposed InP with 30 W for 10sec, the PR signals include a peak $(E_{Ar})$ that is located at 1.336 eV. We think that this peak was originated shallow level related to $V_In-V_P$. And we compared this level with the level obtained by surface photovoltage spectroscopy (SPV) measurement. The result of the PR agrees well with that from SPV. Additionally, Ar plasma induced phosphorus vacancy is related to shallow level. Therefore, the change of surface electric field are attributed to the shallow level. This level is caused by the existence of phsophorus vacancy on InP surface.