Hardening Effect of GaP1-xNxand GaAs1-xNxAlloys by Adding Nitrogen Atoms

Autor: Yuzo Furukawa, Kenji Momose, Kaoru Ojima, A. Utsumi, Kunio Aiki, Hiroo Yonezu, Yasuhiro Fujimoto
Rok vydání: 2002
Předmět:
Zdroj: Japanese Journal of Applied Physics. 41:7301-7306
ISSN: 1347-4065
0021-4922
Popis: We investigated the strain relaxation process of GaP1-xNx/GaP and GaAs1-xNx/GaAs in order to clarify their mechanical characteristics by adding nitrogen atoms. It was observed by transmission electron microscopy (TEM) that the critical thicknesses were greater and the generation rates of the misfit dislocations were slower in the GaP1-xNx and GaAs1-xNx layers than those in the GaP layer with a similar lattice mismatch. The critical thickness of the GaAs1-xNx layer was greater than that of the GaP1-xNx layer for the same nitrogen composition of 2%. The direction of higher crack density was orthogonal to that of the higher misfit dislocation density. These results indicate that the propagation of dislocations is prevented in III–V–N alloys such as GaP1-xNx and GaAs1-xNx, so that these alloys are harder than III–V compounds that lack nitrogen atoms. This feature could be attributed to the dislocation pinning and alloy hardening effects due to nitrogen atoms.
Databáze: OpenAIRE