等离子体氮钝化GaSb材料表面特性研究

GaSb materials are widely used in optoelectronic devices due to their high electron and hole mobility. However, the surface states of GaSb materials seriously affect the properties of materials, and hinder the improvement of the performance of GaSb based devices. Nitrogen passivation technology can solve the problems of surface states and improve the luminescent properties of GaSb materials. In addition, the influence of passivation conditions on the passivation effect can not be neglected, for example, the surface states are not completely removed when the etching cycle is insufficient, and the best N passivation conditions can effectively improve the luminescent properties of GaSb materials. In this paper, we use PEALD system to nitrogen passivation by layer by layer etching method for GaSb, and the influence of etching cycle on GaSb effect in passivation process is discussed. The optical properties, surface morphology and elemental states of the passive samples were analyzed by means of photoluminescence (PL), atomic force microscopy (AFM) and X ray photoelectron spectroscopy (XPS). It is found that，the best etching cycle (200) shows that the sample has the highest PL emission intensity and the best passivation effect. When the etching cycle is not enough (100), the luminous intensity of the sample is slightly lower, and the passivation effect is slightly weaker. When the etching cycle is higher (300 and 400), the spectral intensity decreases gradually with the increase of the number of etching cycles, and the surface roughness increases gradually, that is to say, the passivation effect is weakening gradually. The influence of etching period on Photoluminescence of nitrogen passivated GaSb is studied, which find the optimum conditions of nitrogen passivation and effectively improve the optical properties of GaSb materials, that provides an important basis for the study of high performance GaSb based optoelectronic devices.