Influence of Passivation Layers for Metal Grating-Based Quantum Well Infrared Photodetectors
LIU Dong1, FU Yong-Qi1**, YANG Le-Chen1, ZHANG Bao-Shun2, LI Hai-Jun2, FU Kai2, XIONG Min2
1School of Physical Electronics, University of Electronic Science and Technology of China, Chengdu 610054 2Suzhou Institute of Nano-technology and Nano-bionics, Chinese Academy of Sciences, Suzhou 215123
Influence of Passivation Layers for Metal Grating-Based Quantum Well Infrared Photodetectors
LIU Dong1, FU Yong-Qi1**, YANG Le-Chen1, ZHANG Bao-Shun2, LI Hai-Jun2, FU Kai2, XIONG Min2
1School of Physical Electronics, University of Electronic Science and Technology of China, Chengdu 610054 2Suzhou Institute of Nano-technology and Nano-bionics, Chinese Academy of Sciences, Suzhou 215123
To improve absorption of quantum well infrared photodetectors (QWIPs), a coupling layer with metallic grating is designed and fabricated above the quantum well. The metal grating is composed of 100 nm Au film on top, and a 20-nm Ti thin layer between the Au film and the sapphire substrate is coated as an adhesion/buffer layer. To protect the photodetector from oxidation and to decrease leakage, a SiO2 film is deposited by means of plasma-enhanced chemical vapor deposition. A value of about 800 nm is an optimized thickness for the SiO2 applied in the metallic grating?based mid-infrared QWIP. In addition, a QWIP passivation layer is studied experimentally. The results demonstrate that the contribution from the layer is positive for metal grating coupling with the quantum well. The closer the permittivity of the two dielectric layers (SiO2 and the passivation layers), and the closer the two transmission peaks, the greater the QWIP enhancement will be.
LIU Dong, FU Yong-Qi, YANG Le-Chen, ZHANG Bao-Shun, LI Hai-Jun, FU Kai, XIONG Min. Influence of Passivation Layers for Metal Grating-Based Quantum Well Infrared Photodetectors[J]. 中国物理快报, 2012, 29(6): 60701-060701.
LIU Dong, FU Yong-Qi, YANG Le-Chen, ZHANG Bao-Shun, LI Hai-Jun, FU Kai, XIONG Min. Influence of Passivation Layers for Metal Grating-Based Quantum Well Infrared Photodetectors. Chin. Phys. Lett., 2012, 29(6): 60701-060701.
2012, Vol. 29 
