Microstructural characterization of α-GaN films grown on sapphire by organometallic vapor phase epitaxy

Applied Physics Letters - Tập 66 Số 10 - Trang 1252-1254 - 1995
Weijin Qian1, Marek Skowroński1, Marc De Graef1, K. Doverspike2, L.B. Rowland2, D. Kurt Gaskill2
1Department of Materials Science & Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213
2Laboratory for Advanced Material Synthesis, Naval Research Laboratory, Washington, DC 20375

Tóm tắt

Microstructure of α-GaN films grown by organometallic vapor phase epitaxy on sapphire substrates using low temperature AlN (or GaN) buffer layers has been studied by transmission electron microscopy. The defects which penetrate the GaN films are predominantly perfect edge dislocations with Burgers vectors of the 1/3〈112̄0〉 type, lying along the [0001] growth direction. The main sources of threading dislocations are the low angle grain boundaries, formed during coalescence of islands at the initial stages of GaN growth. The grain sizes range from 50 to 500 nm, with in-plane misorientations of less than 3°. The nature of these threading dislocations suggests that the defect density would not likely decrease appreciably at increasing film thickness, and the suppression of these dislocations could be more difficult.

Từ khóa


Tài liệu tham khảo

1987, Mater. Res. Soc. Symp. Proc., 97, 409

1986, Appl. Phys. Lett., 48, 353

1981, Jpn. J. Appl. Phys., 20, L545

1993, J. Cryst. Growth, 127, 136

1993, J. Appl. Phys., 73, 189

1983, Appl. Phys. Lett., 42, 427

1989, J. Cryst. Growth, 98, 209

1994, Appl. Phys. Lett., 65, 2302

1993, Appl. Phys. Lett., 62, 702

1991, J. Cryst. Growth, 115, 628

1993, J. Appl. Phys., 73, 4700

1994, Mater. Res. Soc. Symp. Proc., 339, 477

1991, J. Cryst. Growth, 107, 509

1971, J. Cryst. Growth, 9, 158

1993, J. Appl. Phys., 74, 4430

Thông tin
Thông tin xuất bản

Applied Physics Letters

Tập 66 Số 10

1252-1254

Thông tin tác giả