开展了 InAs基 InAs/Ga(As)Sb II类超晶格长波红外探测器的湿法腐蚀工艺研究.选择的腐蚀液由柠檬酸、磷酸和过氧化氢组成,先后在InAs、GaSb体材料和 InAs/Ga(As)Sb II类超晶格上进行了湿法腐蚀实验,分别获得了其最佳的腐蚀液组分及配比.使用优化的磷酸系腐蚀液对 InAs/Ga(As)Sb II类超晶格进行腐蚀,获得的腐蚀表面粗糙度仅为 1 nm.然后使用改进的工艺制备了 50％截止波长为 12 μm的超晶格长波单元器件,实验结果表明磷酸系腐蚀液可以获得低暗电流密度的 InAs基 InAs/Ga(As)Sb II类超晶格长波红外探测器.另外,在 81 K下,该探测器的表面电阻率(ρSurface)为 4.4 × 103Ωcm.

Wet chemical etching of InAs-based InAs/Ga(As)Sb superlattice long wavelength infrared photodiodes was studied in this paper.The etching experiments using citric acid,orthophosphoric acid and hydrogen peroxidewere carried out on InAs,GaSb bulk materials and InAs/Ga(As)Sb superlattices with different solution ratios. An optimized etching solution for the InAs-based superlattices has been obtained. The etched surface roughness is only 1 nm. InAs-based superlattice LWIR detectors with 50 % cut-off wavelength of 12 μm were fabricated. The photodetectors etched with optimized solution ratio show low surface leakage characteristic.At 81 K temperature, the surface resistivity ρSurface of the detector is 4. 4 × 103 Ωcm.