The electrical and optical characteristics of Pt diffusion in n-type GaN film were investigated. The diffusion extent was characterized by the SIMS technique. The temperature-dependent diffusion coefficients of Pt in n-GaN were equal to 4.158 x 10−14, 1.572 x 10−13 and 3.216 x 10−13cm2/s at 650, 750 and 850C, respectively. The Pt diffusion results could be described by:

D (cm2/s) = 6.627 x 10−9exp[-0.914(eV)/kT]

These results indicated that the major diffusion mechanism of Pt in GaN was possibly interstitial diffusion. In addition, it was also observed that the Pt atom could be a donor because the carrier concentration in Pt-diffused GaN was higher than that in un-diffused GaN.

The Characteristics of Platinum Diffusion in n-Type GaN. D.H.Yeh, L.Z.Hsieh, L.B.Chang, M.J.Jeng: Applied Surface Science, 2007, 253[16], 6910-4