共查询到17条相似文献,搜索用时 186 毫秒
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采用射频磁控溅射工艺在扩镓硅基上溅射Ga2O3薄膜氮化反应组装GaN薄膜,研究硅基扩镓时间对GaN薄膜晶体质量的影响.利用红外透射谱(FHR)、X射线衍射(XRD)、扫描电镜(SEM)、光电能谱(XPS)和荧光光谱(PL)对生成的GaN薄膜进行组分、结构、表面形貌和发光特性分析.测试结果表明:采用此方法得到六方纤锌矿结构的GaN晶体膜.同时显示:在相同的氮化温度和时间下,随着硅基扩镓时间的增加,薄膜的晶体质量和发光特性得到明显提高.但当硅基扩镓时间进一步增加时,薄膜的晶体质量和发光特性却有所降低.较适宜的硅基扩镓时间为40min. 相似文献
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本文通过在ZnO/Si(111)衬底上,利用JCK-500A型射频磁控溅射系统溅射氧化镓靶得到氧化镓薄膜.然后将硅基Ga2O3置于管武石英炉中,在850℃的氨化温度下氨化15min后,成功制备出GaN薄膜,该薄膜由正六边形的晶粒组成.X射线衍射(XRD)表明GaN具有六方纤锌矿结构,晶格常数为a=0.318nm和c=0.518nm.X射线光电子能谱(XPS)的测试确定了样品中Ga-N键的形成,并且Ga和N的化学计量比为1:1.用扫描电镜(SEM)和原子力显微镜(AFM)观察发现,样品表面非常光滑和平整.透射电镜(TEM)表明薄膜由正六边形晶粒组成.选区电子衍射(SAED)进一步验证了GaN薄膜的六方纤锌矿结构.最后,简单地讨论了其生长机制. 相似文献
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利用射频磁控溅射法在Si(111)衬底上先溅射ZnO中间层,接着溅射Ga2O3 薄膜,然后ZnO/Ga2O3薄膜在管式炉中常压下通氨气进行氮化,高温下ZnO层在氨气的气氛中挥发,而Ga2O3薄膜和氨气反应合成出GaN纳米管.X射线衍射(XRD)测量结果表明利用该方法制备的GaN具有沿c轴方向择优生长的六角纤锌矿结构.利用傅里叶红外光谱(FTIR)研究了所制备样品的光学性质.利用透射电子显微镜(TEM)和选区电子衍射(SAED)观测了样品的形貌和晶格结构. 相似文献
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利用热壁化学气相沉积在Si(111)衬底上获得GaN品绳,采用傅里叶红外吸收谱(FTIR)、扫描电子显微镜(SEM)、选区电子衍射(SAED)、X射线衍射(XRD)和光致发光谱(PL)对晶绳进行组成、结构、形貌和光学特性分析。初步结果证明:在Si(111)衬底上获得择优生长的六方纤锌矿结构的GaN晶绳。SEM显示在均匀的薄膜上出现φ6μm的晶绳,FTIR显示GaN薄膜的主要成分为GaN同时含有少量的C污染,由XRD和SAED的综合分析得出晶绳呈六方纤锌矿单晶结构,PL测试表明晶绳呈现不同于GaN薄膜的发光特性。 相似文献
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Single-crystalline GaN nanorods were successfully synthesized on Si(1 1 1) substrates through ammoniating Ga2O3/Mo films deposited on the Si(1 1 1) substrate by radio frequency magnetron sputtering technique. The as-synthesized nanorods are confirmed as single-crystalline GaN with wurtzite structure by X-ray diffraction (XRD), selected-area electron diffraction (SAED) and high-resolution transmission electron microscopy (HRTEM). Scanning electron microscopy (SEM) displays that the GaN nanorods are straight and smooth with diameters in the range of 100-200 nm and lengths typically up to several micrometers. X-ray photoelectron spectroscopy (XPS) confirms the formation of bonding between Ga and N. The representative photoluminescence spectrum at room temperature exhibits a strong and broad emission band centered at 371.1 nm, attributed to GaN band-edge emission. The growth process of GaN nanorod may be dominated by vapor-solid (VS) mechanism. 相似文献
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Large-scale GaN nanowires were successfully synthesized through ammoniating Ga2O3/Pd films sputtered on the sapphire(001) substrates. X-ray diffraction, scanning electron microscopy, high-resolution transmission electron microscopy, photoluminescence and Raman spectrum were used to characterize the specimens. The results demonstrate that nanowires are single crystal with hexagonal wurtzite structure and have good optical properties. Raman scattering appears broadened and asymmetric compared with those of bulk GaN due to its polycrystalline nature. In addition, the growth mechanism of GaN nanowires is briefly discussed. 相似文献
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Jinhua Chen Huizhao Zhuang Lixia Qin Hong Li Zhaozhu Yang Dongdong Zhang 《Materials Research Bulletin》2008,43(11):2974-2978
A novel rare earth metal seed was employed as the catalyst for the growth of GaN nanorods. Large-scale GaN nanorods were synthesized successfully through ammoniating Ga2O3/Tb films sputtered on Si(1 1 1) substrates. Scanning electron microscopy, X-ray diffraction, transmission electron microscopy, high-resolution transmission electron microscopy, and X-ray photoelectron spectroscopy were used to characterize the structure, morphology, and composition of the samples. The results demonstrate that the nanorods are high-quality single-crystal GaN with hexagonal wurtzite structure. The growth mechanism of GaN nanorods is also discussed. 相似文献
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Cheng-Che Li Dong-Hau Kuo 《Journal of Materials Science: Materials in Electronics》2014,25(3):1404-1409
GaN films have been deposited at 100–400 °C substrate temperature on Si (100) and sapphire (0001) substrates by RF reactive sputtering in an (Ar + N2) atmosphere. A (Ga + GaN) cermet target for sputtering was made by hot pressing the mixed powders of metallic Ga and ceramic GaN. The effects of substrate temperature on the GaN formation and its properties were investigated. The diffraction results showed that GaN films with a preferential (10–10) growth plane had a wurtzite crystalline structure. GaN films became smoother at higher substrate temperature. The Hall effect measurements showed the electron concentration and mobility were 1.04 × 1018 cm?3 and 7.1 cm2 V?1 s?1, respectively, for GaN deposited at 400 °C. GaN films were tested for its thermal stability at 900 °C in the N2 atmosphere. Electrical properties slightly degraded after annealing. The smaller bandgap of ~3.0 eV is explained in terms of intrinsic defects and lattice distortion. 相似文献
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We report crack-free and single-crystalline wurtzite GaN heteroepitaxy layers have been grown on Si (111) substrate by metal-organic chemical vapor deposition(MOCVD). Synthesized GaN epilayer was characterized by X-ray diffraction(XRD), atomic force microscope (AFM) and Raman spectrum. The test results show that the GaN crystal reveals a wurtzite structure with the <0001> crystal orientation and XRD ω-scans showed a full width at half maximum (FWHM) of around 583 arcsec for GaN grown on Si substrate with an HT-AlN buffer layer. In addition, the Raman peaks of E2high and A1(LO) phonon mode in GaN films have an obvious redshit comparing to bulk GaN eigen-frequency, which most likely due to tensile strain in GaN layers. But the AO phonon mode of Si has a blueshit which shows that the Si substrate suffered a compressive strain. And we report that the AlN buffer layer plays a role for releasing the residual stress in GaN films. 相似文献
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Cheng-Che Li Dong-Hau Kuo 《Journal of Materials Science: Materials in Electronics》2014,25(4):1942-1948
Mg-doped GaN (Mg–GaN) films have been deposited on Si (100) substrates by radio-frequency reactive sputtering technique with single cermet targets. The targets can be made by hot pressing the mixture of metallic Ga and Mg powders and ceramic GaN powder. X-ray diffraction results showed that Mg–GaN films had a wurtzite structure with a preferential nonpolar $ m - \left( {10\bar{1}0} \right) $ growth plane. Mg–GaN with 10.2 % Mg has transformed into p-type conductivity and has the carrier concentration of 9.37 × 1016 cm?3, the highest mobility of 345 cm2 V?1 s?1, and the highest conductivity of 3.23 S cm?1. The band gap of Mg–GaN films retrieved from the absorption spectra is 2.93–3.06 eV. Furthermore, we have also fabricated a totally sputtering-made and cost-effective GaN diode with the ideality factors of 5.0 and 4.9 for the as-deposited and the annealed, respectively. 相似文献