High quality GaN thin films were grown by rf-plasma assisted molecular beam epitaxy on intermediate-temperature buffer layer (ITBL). The electrical properties of the GaN films were systematically characterized by Hall coefficients and low-frequency noise measurements. The results show a systematic change in the electrical properties, which vary as a function of the thickness of ITBL. Room temperature Hall mobility increases steadily from 87 cm2V-1s-1, for GaN film grown on conventional low-temperature buffer layer (LTBL), to 390 cm2V-1s-1, for sample grown with an 800-nm-thick ITBL inserted between the LTBL and the top epitaxial layer. The Hooge parameter reaches a minimum value of 7.34×10-2 for an optimal ITBL thickness of 800nm. The observed improvements in the electrical properties are attributed to the relaxation of residual strain in the overgrown GaN by utilizing an ITBL.
|Number of pages||5|
|Publication status||Published - Jan 1 2001|
|Event||2001 IEEE Hong Kong Electron Devices Meeting - Hong Kong, China|
Duration: Jun 30 2001 → …
|Conference||2001 IEEE Hong Kong Electron Devices Meeting|
|Period||6/30/01 → …|
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