Silicon impurity-related effects on structural defects in III-V nitrides

The Si doping effect on structural defects in III-V nitrides has been investigated. It has been found that this effect causes the strain relaxation in GaN(AlGaN)Al2O3 structures, reduces compressive stress, decreases the dislocation density by several times. Moreover, the nano- and micropipe density has been observed to decrease by several orders of magnitude at a critical Si concentration (about 8x10(18) cm(-3)) as well as reduces the domain size of mosaic structures, As a result, the structure properties of GaN and AlGaN layers have been improved. Moreover, a mobility of charge carriers has increased. The increase from 50 cm (2)V(-1)s(-1) to 600 cm(2)V(-1)s(-1) and from 20 cm (2)V(-1)s(-1) to 100 cm(2)V(-1)s(-1) in GaN and AlGaN, respectively, at low Si concentrations (< 10(18) Cm-3) is conditioned not only by improvement in the structure properties, but by potential barrier reduction in mosaic structures as well.