退火温度对硅基GaN薄膜质量的影响

Effects of Annealing Temperature on the Properties of GaN Films on Si Substrates

采用电泳沉积法在Si(111)衬底上制备GaN薄膜,并研究退火温度对GaN薄膜晶体质量、表面形貌和发光特性的影响。傅立叶红外吸收谱(FTIR)、X射线衍射(XRD)和扫描电镜(SEM)的测试结果表明所得样品为六方纤锌矿结构的GaN多晶薄膜,随退火温度的升高,晶粒尺寸增大,结晶化程度提高。室温下光致发光谱的测试发现了位于367 nm处的强发光峰和437 nm处的弱发光峰,其发光强度随退火温度的升高而增强,但发光峰的位置并不发生移动。

GaN films were fabricated on Si （111） substrates by electrophoretic deposition （EPD） technique, and the effects of the annealing temperature on the crystal quality, morphology and optical property of the GaN films are investigated. The measurements of the Fourier transform infrared spectroscopy （FTIR）, X-ray diffraction （XRD） and scanning electron microscopy （SEM） indicate that the as-grown films are polycrystalline GaN with hexagonal wurtzite structure, moreover, the diameters of the GaN crystallites become larger and the crystal quality of the GaN rims is improved with the increase of annealing temperature. Photoluminescence （PL） spectra at room temperature show a very strong emission peak at 367 nm and a weak emission peak at 437 nm. When raising the annealing temperature, the two emission peaks become more intense, while their locations don＇t change.