The Study Of The Properties Of Si Substrate GaN LED Associated With The Film Transferring

The InGaAlN MQW LEDs play more and more important roles in our daily life, it has been applied in a lot of fields,such as back lightting,traffic signal lamp,and outdoor display,and so on.InGaAlN films grown on Al₂O₃ or SiC and its device, have been realized industrialization about a decade years ago,in America and Japan one after another.The industrialization of the growth of InGaAlN MQW LED films on Si substrate and the manufacture of the emission device has realized in china in the recent years,it is a very good news for the researchers all over the world. Wheather the InGaAlN MQW LED is grown on Al₂O₃ or SiC,research and improve its properties is a hard task forever.Compared with the tow others substrates,the study of the properties of the InGaAlN LEDs grown on Si has a long way need to go.So,it is very important to deeply study the properties of the LEDs grown on Si.In this thesies,we use the wafer-bonding or the sputtering technology combine with the lift-off technology,have successfully transfered the InGaAlN MQW LED film from the Si(111)substrate to another new submount,and have manufactured the vertical structure LED devices.At the same time,we have investigated the properties of the vertical structure devices deeply,especially we have studied the associated strain problem.The content of the study and the significant results are followed as:1,In the second chapter,the EL spectram of the vertical structure LEDs chip detected at various different spacial angle have been investigated.The multiple peak of the spectram of the vertical chip is derived from the interference,and the density of the interference peak could indicate the thickness uniformity of the P type layer,the intensity of the interference peak could indicate the reflectivity of the P type ohmic contact metal.2,In the third chapter,the different strain and associated properties between the LED film grown on Si(111)substrate,transferred to new submount and the freestanding film have been investigated.It indicate that when the film in different status it will appear different structural,optical and electrical properties.Sputtering a thick metal layer on the LED film wafer,and then chemical etching the Si substrate, the LED films were successfully transferred from Si(111)substrate to the metal submount,and has obtained the vertical structure LED on metal substrate.By control the thermal expansion efficiency and the sputtering temperature we have realized the control of the stress state in the LED film.3,In the fouth chapter,the changes of the properties before and after a long time reverse bias of the chip have been investigated,the changes of the properties before and after a long time reverse bias of the chip have been investigated too.The changes of the properties is derived from the variation of the distribution of the carrier and the space charge region.4,In the fifth chapter,the optical and electrical difference between the LED at 300K and at 413K,the optical and electrical difference between the LED chip's at 10K and at 300K,the optical and electrical difference between the LED lamp after roughening the epoxy surface at 10K and at 300K,the optical and electrical difference between the aged LED at different condition and the LED without aging have been investigated.It indicate that the bonding metal will arose obvious change of the strain of the transferred LED film,and the space charge region,carrier distribution,emission well layer,and so on will appear a abvious change,while change the ambient temperature.