采用低温分子束外延法(LT-MBE)制备出Ga0.946Mn0.054As稀磁半导体(DMS)薄膜.通过X射线吸收谱(XAS)研究影响Ga0.946Mn0.054As薄膜性质的主要缺陷Mn间隙原子(Mn1)和As反位原子(AsGa).实验结果表明,在较低生长温度(Ts=200℃)下Ga0.946Mn0.054As晶格中缺陷分布以As反位原子(AsGa)为主;较高生长温度(Ts>230℃)时样品中主要缺陷是Mn间隙(Mn1)原子.同时,在较高低温退火温度(250℃)下可以使样品内部Mn1向表面大量析出,减少反铁磁相,达到最高居里温度(130 K).XAS结果还表明,退火可以使得表面的AsGa缺陷脱附,驱动周围的Mn1原子填补AsGa缺陷留下的空位,提高MnGa原子浓度.%The influence of the major compensating defects As antisites (AsGa) and Mn interstitials (Mn1) in the Ga0.946Mn0.054 As diluted magnetic semiconductor (DMS) were studied by X-ray absorption spectra (XAS). The experimental results show that the defects in Ga0.946Mn0. 054As grown at lower temperature ( Ts = 200℃ ) is mainly AsGa, but at Ts ＞ 230℃ Mn1 is the major defects. On the other hand, a higher LT-annealing temperature (250℃) can remove Mn1 out of the Ga0.946 Mn0.054As lattice, and the highest Curie temperature (Tc = 130 K) is reached. Moreover, it is indicated that the LTannealing process can increase the number of MnGa atoms by reducing the concentration of AsGa defects and driving Mn1 defects to fill up the holes left by AsGa.
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