采用双色单铟柱结构的II类超晶格红外探测器件在台面成型过程中加工难度大且易于产生损伤, 影响器件的性能。针对此问题进行了低损伤、高深宽比II类超晶格材料的台面刻蚀技术研究。首先建立一种损伤评判机制, 判断现有工艺刻蚀后材料是否发生反型。然后通过优化光刻胶厚度、变功率分步刻蚀的方式, 实现低损伤、高深宽比II类超晶格材料的台面刻蚀, 同时有效解决单次刻蚀深台面时易堆积生成物以及侧壁过于陡峭等工艺问题。台面中心间距为20 m, 刻蚀深度超过8 m, 缝隙深宽比可达2。基于此台面制备的器件具有明显的双阻抗特征。其中, 长波阻抗峰值为100 MΩ, 并且I-V曲线中长波侧的平坦区超过100 mV。从电学角度初步判断该器件具有双色探测的能力, 验证了本文工艺的可行性。

The fabrication of type-II superlattice infrared detectors with a dual color single indium column structure is difficult and prone to damage during the mesa forming process, which affects the performance of the device. In order to solve this problem, the mesa etching technology for type-II superlattice materials with low damage and high aspect ratio was studied. Firstly, a damage judgment mechanism is established to determine whether the material has inversion after etching in the existing process. By optimizing the photoresist thickness and variable power step etching, the mesa etching of type-II superlattice materials with low damage and high aspect ratio is realized, while effectively solving the process problems such as easy accumulation of products and excessively steep sidewalls in single etching of deep mesas. The distance between centers of mesa is 20 m. Etching depth exceeds 8 m. The gap depth to width ratio can reach 2. The devices subsequently fabricated on this mesa have significant dual impedance characteristics, with a peak long wave impedance of 100 MΩ, and a flat region on the long wave side of the I-V curve exceeding 100 mV. From the perspective of electricity, it is preliminarily judged that the detector has the ability of dual color detection, and the feasibility of this process is verified.