Inductively coupled CH 4 /H 2 plasma etching process for mesa delineation of InAs/GaSb type-II superlattice pixels

Micro & nano letters

article

Sona Das¹  Utpal Das² 

[1] Department of Electronics and Communication Engineering, K.L University;Department of Electrical Engineering, Indian Institute of Technology Kanpur

关键词: indium compounds;    gallium compounds;    passivation;    semiconductor superlattices;    dark conductivity;    sputter etching;    photodiodes;    photodetectors;    current density;    III-V semiconductors;    micro-optics;    optical fabrication;    optical arrays;    plasma materials processing;    optical polymers;    mesa etched+SU-8 polymer passivated type-II superlattice photodiodes;    InAs/GaSb type-II superlattice pixel arrays;    mesa delineation technique;    Inductively coupled methane-hydrogen plasma etching process;    Arrhenius plot;    bulk tunnelling current;    dark current density;    next-generation infrared focal plane arrays;    size 10.0 mum;    temperature 70.0 K;    voltage 0.2 V;    electron volt energy 13.0 meV;    depth 2.4 mum;    InAs-GaSb;   

DOI  :  10.1049/mnl.2018.5549

学科分类：计算机科学（综合）

来源: Wiley

【 摘 要 】

An inductively coupled plasma etching process for delineation of InAs/GaSb type-II superlattice pixels is presented. An optimised etch recipe without alternate plasma cleaning step showed an etch rate as high as 0.11 μm/min that results in smooth vertical sidewalls for the type-II superlattice pixel arrays with 10 μm pitch size and 2.4 μm deep trenches. At 70 K, the dark current density for the mesa etched + SU-8 polymer passivated type-II superlattice photodiodes was found to be 0.11 A/cm 2 at an applied reverse bias voltage of 0.2 V. The activation energy of 13 meV obtained from the Arrhenius plot and a variable area diode array technique showed that the measured dark current is mainly attributed to bulk tunnelling current. This technique of mesa delineation for the type-II superlattice pixel arrays with small pitch size is a viable option in realising next-generation infrared focal plane arrays.

【 授权许可】

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