MBE生长轻掺硅GaAs材料光荧光谱杂质特性研究

Photoluminescence Study on the Impurity Characterization of Lightly Si-Doped GaAs Materials Grown by Molecular Beam Epitaxy

采用低温光荧光谱测试方法，研究了ＭＢＥ生长的轻掺硅ＧａＡｓ材料的杂质特性，并结合Ｈａｌｌ测量结果，讨论了ＭＢＥ关键生长条件Ⅴ／Ⅲ束流比等对Ｓｉ在ＧａＡｓ中掺杂特性的影响，研究表明掺杂元素Ｓｉ在ＧａＡｓ中起两性（施主或受主）杂质作用，适当提高Ⅴ／Ⅲ束流比可以抑制Ｓｉ的自补偿效应，从而减小载流子的补偿度，进一步提高迁移率。通过优化生长条件，本实验已获得了杂质浓度小于１０１２ｃｍ－３，７７Ｋ下迁移率大于１．６×１０５ｃｍ２／Ｖ·ｓ的高纯、高迁移率ＧａＡｓ材料。

The photoluminescence study on the impurity characterization of lightly Si-doped GaAs epitaxial materials grown by MBE has been carried out. In combination with the Hall measurement results, some key growth conditions for effects on the electrical properties of GaAs, have been discussed. In the low doping range (n<1 × 1015 cm-3 ), the Na/Nd values decrease and electron mobility increase with the increase of Ⅴ/Ⅲ flux ratio. This may be related to the reduced incorporation of compensating acceptors and Si self-compensation effects. The GaAs materials with high mobility (77 K) of 1. 6×105cm2/Vs have been obtained.