化學氣相沈積法製備氮化鎵奈米線及其特性分析

The Preparation and Characterization of GaN Nanowire Grown by Chemical Vapor Deposition Method

10.6409/JMSE.200612.0235

施承達(C.D. Shin)；李國豪(K.H. Lee)；陳引幹(I.G. Chen)

奈米線 ； 場發射 ； 紅位移 ； Nanowires ； field emission ； redshift

材料科學與工程

38卷4期（2006 / 12 / 01）

235 - 240

繁體中文

本研究使用墊當催化劑，以氣－液－固(VLS)機制在矽基板上成功長出氮化鎵奈米線。藉由改變通入載氣流量的比例，則可以使奈米線分布均勻和其密度、長度增加。由表面形貌分析，可以觀察到氫氣載氣流量比例的提升，當氫氣達到400 sccm以上時，奈米線結構即有明顯改變，形成寬度約爲100 nm之奈米帶，且其中一面具有兩排奈米凸起物，其凸起物產生與製程結束後通入氨氣持續成長有關。此凸起結構亦能將場發射起始電場降低至8.5 V/μm。發光特性部分，氫氣流量比例的提升，其光激發光譜的鋒值會呈現紅移的現象，從3.38紅移至3.25eV，推測可能是因氫氣造成氮化鎵內部產生鎵空孔有關。

GaN nanowires (NWs) had been synthesized on the platinum coated silicon (111) substrate by the chemical vapor deposition (CVD) method in the different flow rate ratios of NH3/H2 carrier gases. SEM images show that when H2 flow rate was 400 sccm, the nanowires had grown nano protrusions on the surface and the diameter of nanowire was about 100 nm. The nano protrusion would have associated with the residual of NH3 ambient in the cooling process. The nanowires with nano protrusions exhibited the lowest turn on field~8.5V/um in field emission measurement. The redshift of the PL peak position from nanowires when H2 flow rate increased mayt have been affect by Ga vacancy in nanowires.