Residual Strain and Electronic Characteristics of Si-doped GaN

The residual strain and the damage induced by Si implantation in GaN samples have been studied, as well as the electronic characteristics. These as-grown samples are implanted with different doses of Si(1× 1014cm-2, 1×1015cm-2or 1×1016cm-2, 100 keV) and following annealed by rapid thermal anneal(RTA) at 1 000℃or 1 100℃for 60 s. High resolution X-ray diffractometer(HRXRD) measurement reveals that the damage peak induced by the implantation appears and increases with the rise of the impurity dose, expanding he crystal lattice. The absolute value of biaxial strain decreases with the increase of the annealing temperature for the same sample. RT-Hall test reveals that the sample annealed at 1 100℃acquires higher mobility and higher carrier density than that annealed at 1 000℃, which reflects that the residual strain(or residual stress) is the main scattering factor. And the sample C3(1×1016cm-2and annealed at 1 100℃) acquires the best electronic characteristic with the carrier density of 3.25×1019cm-3and the carrier mobility of 31 cm2/(V·s).