Structural characterization of bulk GaN crystals grown under high hydrostatic pressure

被引：68

作者：

LilientalWeber, Z ^{[1
]}

Kisielowski, C ^{[1
]}

Ruvimov, S ^{[1
]}

Chen, Y ^{[1
]}

Washburn, J ^{[1
]}

Grzegory, I ^{[1
]}

Bockowski, M ^{[1
]}

Jun, J ^{[1
]}

Porowski, S ^{[1
]}

机构：

[1] POLISH ACAD SCI, HIGH PRESSURE RES CTR UNIPRESS, WARSAW, POLAND

来源：

JOURNAL OF ELECTRONIC MATERIALS | 1996年 / 25卷 / 09期

关键词：

bulk; GaN; crystal polarity; excess Ga; microstructure; planar defects; surface roughness;

D O I：

10.1007/BF02655397

中图分类号：

TM [电工技术]; TN [电子技术、通信技术];

学科分类号：

0808 ; 0809 ;

摘要：

This paper describes TEM characterization of bulk GaN crystals grown at 1500-1800K in the form of plates from a solution of atomic nitrogen in liquid gallium under high nitrogen pressure (up to 20 kbars). Their x-ray rocking curves for these crystals were in the range of 20-30 arc-sec. The plate thickness along the c axis was about 100 times smaller than the nonpolar growth directions. A substantial difference in material quality was observed on the opposite sides of the plates normal to the c direction. On one side the surface was atomically flat, while on the other side the surface was rough, with pyramidal features up to 100 nm high. The polarity of the crystals was determined using convergent-beam electron diffraction. The results showed that, regarding the long bond between Ga and N along the c-axis, Ga atoms were found to be closer to the flat side of the crystal, while N atoms were found to be closer to the rough side. Near the rough side, within 1/10 to 1/4 of the plate thickness, there was a high density of planar defects (stacking faults and dislocation loops decorated by Ga/void precipitates). A model explaining the defect information is proposed.

引用

页码：1545 / 1550

页数：6