不同磷压下生长的MOVPE n-GaP中的Ni杂质浓度

THE CONCENTRATION OF IMPURITY Nin-GaP GROWN BY MOVPE UNDER DIFFERENT PH_3 PRESSURES

用二次离子质谱(SIMS)技术测定了不同磷压下生长的MOVPE n-GaP中的Ni杂质相对浓度.所得结果与用结电容技术测得的同一系列样品中存在的一个具有光-热激发行为的深中心D_5的浓度变化规律相符,为将D_5中心的化学本质指认为Ni(d^9)提供了直接证据.对MOVPE n-Gap中Ni杂质随磷压变化规律作了热化学分析,对实测结果得到了合理解释.

The relative concentrations of impurity Ni in MOVPE n-GaP grown under different pressures of PH_3are measured with SIMS technique. The results agree well with that of the deep centre D_5, which expresses obviously photo-thermal excitation behaviour, in the same series of samples measured by juction capacitance techniques. The results give a diract proof for assigning D_5 centre to Ni(d^9).The variation of the concentration of Ni with the phosphorous pressurd used during growth are explained with a thermodynamic argument.