Investigation and Fabrication of GaInNAs Near Infrared Photodetectors

• Main Authors: Bing-Yang Chen, 陳秉揚
• Other Authors: Yan-Kuin Su
• Format: Others
• Language: en_US
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/76389198786020860385

碩士 === 國立成功大學 === 微電子工程研究所碩博士班 === 93 === 　　In this thesis, we used the novel GaInNAs material as the absorption layer of photodetector grown on GaAs substrate by Metal Organic Vapor Phase Epitaxy (MOVPE). Incorporating proper amount of indium and nitrogen into GaAs will let GaInNAs be lattice-matched on GaAs substrate and decrease the defects due to lattice mismatch. Also, the thicker absorption layer of photodetector will be grown to increase the absorption efficiency. 　　Incorporating small amount of nitrogen into GaInAs will lower the quality of material. The parameters of the GaInNAs and GaInAs epilayer with the same emission wavelength grown on GaAs substrate were compared using HR-XRD. Then, the GaInNAs and GaInAs MSM photodetectors were fabricated and compared. It was found that the performance of GaInNAs MSM photodetector was better than that of GaInAs MSM photodetector. 　　The ITO material was chosen to be the Schottky contact of 1.2um GaInNAs MSM photodetector. It was found that the transmittance of the ITO film deposited by RF-sputtering with O2 achieved a value of 96% but the photo/dark current contrast ratio of MSM photodetector that ITO film deposited by RF-sputtering with N2 was the largest. Furthermore, the density of interface states and the leakage current of MIS capacitors with sputtering SiO2 film were measured and it was shown that the quality of SiO2 deposited by RF-sputtering with O2 improved as the flow rate of O2 increased. The density of interface states and the leakage current of MIS capacitors that the SiO2 film deposited without O2 were 1.099×1013cm-2eV-1 and 3.67×10-2 A/cm2 (at 0.5MV/cm) and those of MIS capacitors that the SiO2 film deposited with higher flow rate of O2 were 9.32×1012cm-2eV-1 and 6.906×10-7 A/cm2 (at 0.5MV/cm), respectively. 　　Finally, the MIS and MIMS photodetectors with sputtering SiO2 layer were fabricated. It could be seen that the photo/dark current contrast ratio of photodetectors increased as the thickness of SiO2 layer increased. The photo/dark current contrast ratio, responsivity, and maximum quantum efficiency of the MIMS photodetector were 69.22, 0.035A/W, and 5%, respectively.