Study On Ohmic Contact Of Semiconductor Lasers Process

This thesis is focused on formation principles, process preparation and measurement method of ohmic contact of GaAs-based material. On the topic of the thesis research background,the internal and external situation of ohmic contact is described on the basis of III-V family material and arsenide material properties and ohmic contact related theory. The ohmic contact performance good or bad influence factors is analysed from two aspects of the theory and technology preparation. Further, the ohmic contact process of n-GaAs and p-GaAs is optimized and analysised. The metallized structures of ohmic contact are adoped with Ni/AuGe/Ni/Au=5/100/35/300nm for n-GaAs and Ti/Pt/Au=30/50/150nm for p-GaAs adoptd, respectively.The influence of rapid thennal annealing process on the ohmic contact is discussed. The different conditions of experimental samples were measured and calculate through,the rectangular transmission line model(RTLM) method, and the error between measured, value of actual value is analyzed. The electrical properties and physical and chemical reaction of GaAs material ohmic contact under rapid thermal annealing are analyzed by curve of ohmic contact resistance. The scanning electron microscopy(SEM) were employed to measure, the change of surface morphology under different alloy conditions. The808nm semiconductor laser devices are fabricated by using optimized parameters, with the series resistance of0.12and the output power of3W under the maximum working current of4A.This thesis is to provide a theoretical basis and experimental evidence for reducing the series resistance and increasing the output power of the GaAs-based semiconductor laser devices, and also provide important reference for fabricating other GaAs-based semicondor devices.