The Research Of GaInAsSb/GaSb PIN Photodetctor And Production Process

The direct-narrow-band gap of â…¢-â…£ compound semiconductor GalnAsSb has attracted much attention for its applications in the fabrication of light-emitting diode, laser and detector. The quaternary GalnAsSb alloy system has the energy band gap from 0.8 to 8pm, changing with the composition, which can be grown lattice matched on InP , GaSb and InAs substrate, InP span 1.6¹.7μm, InAs span 1.7³.4μm,GaSb span 1.7⁴.3μm, respectively. The quaternary GalnAsSb can be used for the bolometer, IR radar, monitoring of the environment, trace gases and other interesting purpose for its special response wavelength. GalnAsSb infrared detectors are novel compound detectors with advantages of fast response, high sensitivity, high stability, low price, especially its character to work at room temperature.The device technology is studied and tits performance is improved in this dissertation. Major contents and results of the study are abstracted as following:1. The omhnic contact and the annealing condition of p-type GalnAsSb is discussed .Thesamples are analysed with XRD. Test results show that TiPtAu , AuBe and AuZn on GalnAsSb have become omhnic contact before annealing, and those contact restivity become smaller after annealing treatment, reacheing 10^-5 Ω·cm²,even 10^-6Ω·cm². Omhnic contact of TiPtAu is smallest and stablest.2. A new low-toxicity sulfur passivation method, CH₃CSNH₂/NH₄OH solution,is developedfor GalnAsSb detector.Measurement results show reverse currents decreased greatly and dynamic resistance increased up to 25 times.The passivation result are also even better after 217 days, with the equal result of (NH₄)₂S passivation . AES and XPS are used to analyze the GalnAsSb surface before and after treated with CH₃CSNH₂/NH₄OH solution.3. The antireflective film is analyzed. The AR film of Al₂O₃N SiO₂ and ZrO₂ have been prepared on Si substrate by sputtering technique, the reflectance ratio can decrease 53.45% by ZrO₂ AR coating . The results of â… -â…¤ and blackbody detectivity test of GaInAsSb/GaSb PIN infrared photodetectors show that ZrO₂ film is one kind of ideal AR coating, which can result in a significant increase of blackbody detectivity with 60.28%,and 40.04% of SiO₂ AR coating, 48.91% of AL₂O₃ AR coating.