Abstract
在本論文中成功研製以銻為主的三五族化合物半導體光偵測器與累增光二極體.在AlGaAsSb/GaInAsSb 的 PIN異質接面光偵測器中,具有暗電流435nA/-1 V 和 943 nA/-3 V,並在1.94um 的吸收邊緣具有光響應度0.58 A/W,相當於38% 的量子效率.在研究AlGaSb/GaSb/GaInAsSb雙異質接面的累增光二極體時,是以砷銻化銦鎵(GaInAsSb)為吸收層,並且以銻化鎵(GaSb)為累增層.當增益為10時,雜訊因子為4.3,且其在1.94 um 吸收邊緣時的光響應度為0.66 A/W,相當於41%的量子效率.在高頻的量測中,具有上升時間742 ps,脈衝寬度 345 ps,下降時間845 ps,其頻寬約為1.81 GHz.而這些元件都能夠成功的在高頻條件下工作,這是除了InGaAs/InP材料系列以外的令一種適當的選擇.In this thesis, we have demonstrated the elctrical and opticalproperties ofhigh-quality GaSb and AlGaSb materials grown fromSb-rich solutions by LPE.The low-temperature PL spectra isdominated by the transitions of excitonsbound to neutralacceptors and free exciton. The intensity of band A relatedtonative defects can be much reduced at lower growth temperatures.The low concentration and narrow FWHM of line BE4 foe theepitaxial layers are betterthan thoso reported previously.In thethesis, we also report the accurate control of electronconcentrationof GaSb epitaxial layers grown from Sb-richsolutions by LPE. The lowestelectron concentration,5.6e15 cm-3,is obtained by using 12 wt% Te-doped poly-crystalline GaSb inthe undoped GaSb starting material for the GaSb growthsolutiontosuppress or compensate the background hole concentration.On theother hand, we also grow the high-quality GaInAsSb and AlGaAsSbepitaxial layersat 610 C by LPE and application to photodiodes.The fabricated AlGaAsSb/GaInAsSbPIN photodiode exhibit a darkcurrent of 320 nA at 0.5 V, 943 nA at 3 V, respectively,and amaximum photoresponsivity of 0.58 A/W at 1.94 um correspondingto the externalquantum efficiency of 38 %. The pulse responseexhibits in the photodiode witha rise time of 200 ps and apulsewidth of 400 ps. The corresponding basedbandfrequency widthat 3-dB is estimated to be 1.25 GHz which in good agreement withthe calculated value of 1.47 GHz.Finally, we also demonstratedthe AlGaSb/GaSb/GaInAsSb heterostructure separateabsorption andmultiplication avalanche photodiode grown from Sb-rich solutionsby LPE. The AlGaSb/GaSb/GaInAsSb SAM-APD exhibit amultiplicatiobn factor of 4.3at 1.5 V. The optimum of carrierconcnetration and thickness of the GaSb multiplicationlayer andGaInAsSb absorption layer of the SAM-APD. Pulse response for thephotodiodewas tested with a rise time of 742 ps and a pulsewidthof 345 ps. The correspondingbaseband frequency width at 3-dBreduction is broader than 1.81 GHz.