公开(公告)号：US11876147B2

公开(公告)日：2024-01-16

申请号：US16424157

申请日：2019-05-28

申请人： THE REGENTS OF THE UNIVERSITY OF MICHIGAN

发明人： Xianhe Liu ,  Ayush Pandey ,  Zetian Mi

IPC分类号： H01L33/00 ,  H01L33/06 ,  H01L33/32

CPC分类号： H01L33/007 ,  H01L33/0025 ,  H01L33/06 ,  H01L33/325

摘要： An epitaxial growth process, referred to as metal-semiconductor junction assisted epitaxy, of ultrawide bandgap aluminum gallium nitride (AlGaN) is disclosed. The epitaxy of AlGaN is performed in metal-rich (e.g., Ga-rich) conditions using plasma-assisted molecular beam epitaxy. The excess Ga layer leads to the formation of a metal-semiconductor junction during the epitaxy of magnesium (Mg)-doped AlGaN, which pins the Fermi level away from the valence band at the growth front. The Fermi level position is decoupled from Mg-dopant incorporation; that is, the surface band bending allows the formation of a nearly n-type growth front despite p-type dopant incorporation. With controlled tuning of the Fermi level by an in-situ metal-semiconductor junction during epitaxy, efficient p-type conduction can be achieved for large bandgap AlGaN.