Epitaxial Structure Design And Device Fabrication Of GaN Rectifiers On Silicon Substrates

The appearance of GaN power devices is a great attempt of global semiconductor industry,after the approaching theoretical limit of the 1^st generation semiconductor materials.It’s also an inevitable result of the development of the history.Gradually achieving of the extensive applications of GaN power devices in the future fields,such as 5G communication,fats-charging,AI intelligence,makes investigations about GaN power device become attractive frontiers and hotspots of the world.Among them,as an indispensable part of GaN power devices,GaN rectifiers will must have an important position among the development pace of GaN power devices,because its applications in future energy fields such as clean energy collection system and microwave transmission.In this paper,the investigations about the performance of GaN rectifiers came from the perspective of AlGaN/GaN heterojunction structural design and device preduction,respectively.The main achievements are as follow.1.The epitaxial growth of AlGaN/GaN single heterojunction structure on Si（111）substrates was achieved by structural design of buffer layers.And the result of multiple characterization methods shows that,the thickness of AlGaN barrier layer was 17.91 nm with25.08%of Al molar component and 17.48%of the in-planar percentage relaxation.The strong strain state endows the AlGaN/GaN single heterojunction structure with good electrical performance and makes it an ideal object for the production of GaN rectifiers.2.Based on the AlGaN/GaN single heterojunction structure,AlN-inserted layer,GaN-caped layer,Mg-doped or C-doped GaN semi-insulated layer was designed to be inserted into AlGaN/GaN heterojunction structure successively.Influences of every inserted layer were carefully studied from the perspectives both on material properties and device performance.3.Based on the structure of GaN rectifier with best performance,we finally reduced the specific on-resistance by 11.17 mΩ/sq and reduced the reversed leakage current by 5.6×10^-5 A under-20 V reversed voltage through the design of electrode pattern and the applied of edge-terminated structure.