Properties of nitrogen incorporated III-V semiconductors by reactive sputtering.

近年来，含氮III-V化合物如GaAsN、InSbN和GaPN的研究受到了广泛的关注，因为它们的带隙随N组成的变化而变化，在光学器件中具有潜在的应用前景。然而，由于晶体GaAsN和GaPN中的氮成分被限制在不到百分之几，这些合金的光学和电子特性还没有很好地了解。本文的目的是研究用溅射法制备的宽N成分的InSb_<1-x>N_x和GaAs_<1-x>N_x非晶态薄膜。结果如下：在溅射反应器中，通过系统地改变N分压（Ar: N_2= 1:0, 9:1, 1:1,0: 1），从InSb靶材制备了InSb_<1-x>N_x非晶态薄膜。椭偏光谱（SE）证实了氮掺入引起的光学变化。随着N成分的增加，光学带隙能量从0.2 eV转移到1.4 eV。在GaAsN和GaPN晶体中，没有观察到带隙能量随N浓度增加而红移的现象。采用100% N_2溅射法制备了N组分x=0的GaN薄膜。薄膜的结晶度变化很大，从无定形到强（0001）平面优选。在溅射沉积的多晶GaN薄膜中首次观察到光致发光现象。在溅射反应器中，通过系统地改变N分压（Ar: N_2= 1:0、9:1、3:1、1:1、0:1），制备了GaAs靶材GaAs_<1-x>N_x非晶态薄膜。椭偏光谱（SE）证实了氮掺入引起的光学变化。随着N成分的增加，光学带隙能量从1.0 eV增加到3.2 eV。在小氮浓度下，可以观察到GaAsN晶体带隙能量的红移。

Recently much attention has been paid to study of nitrogen-containing III-V compounds such as GaAsN, InSbN and GaPN due to their potential application in optical devices, because their band gap vary widely as a function of the N composition. However, Since the nitrogen composition in crystalline GaAsN and GaPN was limited to less than a few percent, optical and electronic properties of these alloys are not well understood. The aim of this work is to study amorphous InSb_<1-x>N_x and GaAs_<1-x>N_x films with the wide N composition prepared by sputtering. The results are follows.1. Amorphous InSb_<1-x>N_x films were prepared from InSb target by a systematic variation of the N partial pressure (Ar : N_2=1 : 0,9 : 1,1 : 1,0 : 1) in the sputtering reactor. Optical changes, induced by nitrogen incorporation, have been evidenced by spectroscopic ellipsometry (SE). Optical band gap energy shift from 0.2 eV to 1.4 eV with increase of N composition. The red shift of band gap energy with increase of N concentration as observed in crystal GaAsN and GaPN was not observed.2. GaN films of N composition x=0 were prepared from Ga target by sputtering in 100% N_2. The crystallinity of the films varied widely from amorphous to strong (0001) plane preferred. Photoluminescence was first observed from sputter-deposited polycrystalline GaN film.3. Amorphous GaAs_<1-x>N_x films were prepared from GaAs target by a systematic variation of the N partial pressure (Ar : N_2=1 : 0,9 : 1,3 : 1,1 : 1,0 : 1) in the sputtering reactor. Optical changes, induced by nitrogen incorporation, have been evidenced by spectroscopic ellipsometry (SE). Optical band gap energy shift from 1.0 eV to 3.2 eV with increase of N composition. The red shift of band gap energy as observed in crystal GaAsN was observed in the small N concentration.