共查询到20条相似文献,搜索用时 203 毫秒
1.
采用直流反应磁控溅射法以ZnO为缓冲层在Si衬底上制备了AlN/ZnO薄膜。利用台阶仪、X线衍射(XRD)仪和原子力显微镜(AFM)对不同溅射功率下制备的AlN/ZnO薄膜的厚度、结构及表面形貌进行测试表征。结果表明,不同溅射功率下生长的AlN薄膜都沿(002)择优生长,且随着功率的增大,薄膜的沉积速率增加,晶粒长大,AlN薄膜的(002)取向性变好。同时还利用扫描电子显微镜(SEM)对在优化工艺下制得AlN/ZnO薄膜断面的形貌进行表征,结果显示AlN薄膜呈柱状生长。 相似文献
2.
3.
4.
5.
采用反应磁控溅射法,在溅射气压、溅射功率和衬底温度恒定的条件下,通过调控氮氩体积流量比,在单晶Si衬底上制备AlN薄膜。利用X射线衍射仪(XRD)、原子力显微镜(AFM)和场发射扫描电子显微镜(FESEM)研究氮氩体积流量比对AlN薄膜的生长取向、晶体质量及沉积速率的影响规律并分析其机理。结果显示,提高氮氩体积流量比有利于AlN薄膜(002)择优取向的生长,但过高的氮氩体积流量比会降低薄膜的沉积速率。在溅射气压为5 mTorr(1 Torr=133.3 Pa)、溅射功率为500 W、衬底温度为200℃、氮氩体积流量(cm3/min)比为14∶6时,在单晶Si衬底上可以制备出质量较好的,具有良好(002)择优取向的AlN薄膜。研究结果可为反应磁控溅射制备高质量AlN薄膜提供工艺参数设置规律指导。 相似文献
6.
在图形化衬底上以AlN作为缓冲层生长高质量的GaN薄膜,国内相关的报道较少。通过引入两步缓冲层生长方法,在蓝宝石图形衬底上生长基于AlN缓冲层的高质量GaN薄膜,利用低温AlN层生长时内部的缺陷,选择性进行腐蚀,形成衬底与外延层界面间的侧向倒斜角,提高光萃取效率;同时在其上继续生长高温AlN,为后续GaN薄膜提供高质量模板。从外延角度出发,以表面形貌及其上生长的GaN薄膜的晶体质量为衡量依据,优化了低温AlN缓冲层以及高温AlN缓冲层的生长参数,优化后LED样品在20 mA测试电流下的光输出功率较参考样品提升了4%。 相似文献
7.
在蓝宝石(Al2O3)衬底上应用脉冲激光沉积技术(PLD)生长不同厚度的AlN缓冲层后进行GaN薄膜外延生长。采用高分辨X射线衍射仪(HRXRD)和扫描电子显微镜(SEM)对外延生长所得GaN薄膜的晶体质量和表面形貌进行了表征。测试结果表明:相比直接在Al2O3衬底上生长的GaN薄膜,通过生长AlN缓冲层的GaN薄膜虽然晶体质量较差,但表面较平整;而且随着AlN缓冲层厚度的增加,GaN薄膜的晶体质量和表面平整度均逐渐提高。可见,AlN缓冲层厚度对在Al2O3衬底上外延生长GaN薄膜的晶体质量和表面形貌有着重要的影响。 相似文献
8.
在蓝宝石(Al2O3)衬底上应用脉冲激光沉积技术(PLD)生长不同厚度的AlN缓冲层后进行GaN薄膜外延生长。采用高分辨X射线衍射仪(HRXRD)和扫描电子显微镜(SEM)对外延生长所得GaN薄膜的晶体质量和表面形貌进行了表征。测试结果表明: 相比直接在Al2O3衬底上生长的GaN薄膜, 通过生长AlN缓冲层的GaN薄膜虽然晶体质量较差, 但表面较平整; 而且随着AlN缓冲层厚度的增加, GaN薄膜的晶体质量和表面平整度均逐渐提高。可见, AlN缓冲层厚度对在Al2O3衬底上外延生长GaN薄膜的晶体质量和表面形貌有着重要的影响。 相似文献
9.
研究了微波功率和反应腔室压强对微波等离子体化学气相沉积(MPCVD)法生长AlN薄膜质量的影响。采用高温MPCVD法,以N2为氮源,三甲基铝(TMAl)为铝源,在6H-SiC衬底上进行AlN薄膜的外延生长。在不同微波功率和不同反应腔室压强下,外延生长了AlN薄膜样品。生长样品的测试结果表明,在微波功率为4 500 W时,样品(002)面X射线摇摆曲线(XRC)半高全宽(FWHM)为217 arcsec。在反应腔室压强为130 Torr(1 Torr=133.3 Pa)时,样品(002)面XRC的FWHM为216 arcsec。该研究将为以后AlN材料的MPCVD生长提供一些参考。 相似文献
10.
11.
《Electronics letters》2008,44(17):1034-1035
Aluminium nitride (AlN) thin films were deposited on a polycrystalline (poly) 3C-SiC layer by a pulsed reactive magnetron sputtering system. The columnar structure of AlN thin films was observed by FE-SEM. The surface roughness of AlN films on the 3C-SiC layer was 9.3 nm. The X-ray diffraction pattern of AlN films on SiC buffer layers was highly oriented at (002). Full width at half maximum of the rocking curve near (002) reflections was 1.38. The infrared absorbance spectrum indicated that the residual stress of AlN thin films grown on SiC buffer layers was nearly negligible. The 3C-SiC intermediate layers are promising for the realisation of nitride based electronic and mechanical devices. 相似文献
12.
G. S. Sudhir H. Fujii W. S. Wong C. Kisielowski N. Newman C. Dieker Z. Liliental-Weber M. D. Rubin E. R. Weber 《Journal of Electronic Materials》1998,27(4):215-221
Thin films of AlN and GaN were grown by pulsed laser deposition on c-plane sapphire substrates. It is demonstrated that the
structure and surface morphology of layers can actively be controlled by adjusting the nitrogen partial pressure during the
growth. The observed trends in the structural quality of the thin films can be attributed to the changes in the surface diffusion
of adatoms. It is argued that the surface diffusion of adatoms can be influenced by the collisions between the nitrogen gas
molecules and the activated atoms which can reduce the kinetic energy of activated atoms and increase the rate of formation
of immobile surface dimers. Through these nitrogen pressure related effects, thin films with microstructure ranging from crystalline
to amorphous can be produced. The observed similar impact of nitrogen pressure on the growth of GaN and AlN thin films indicates
that a pressure assisted growth procedure is generally applicable to design the surface morphology of group III-nitride thin
films. A minimal surface root mean square roughness of 0.7 nm for amorphous AlN is obtained which compares well with the substrate
roughness of 0.5 nm. Rutherford backscattering spectroscopy of thin films of GaN and AlN showed a large incorporation of oxygen
which was found to reduce the lattice constants of GaN and AlN. 相似文献
13.
采用射频(RF)磁控反应溅射法在Si基底上制备了氮化铝(AlN)薄膜,利用X射线衍射(XRD)、傅立叶红外光谱(FTIR)、扫描电子显微镜(SEM)和纳米力学测试系统研究靶基距对AlN薄膜取向性、微结构、形貌和力学性能的影响。结果表明,靶基距较大时,形成的AlN薄膜为非晶态,薄膜表面较疏松;随着靶基距的减少,AlN薄膜变为多晶态,且具有(100)择优取向;随着靶基距的进一步减少,薄膜结晶质量变好,晶粒变大,薄膜变得更致密,择优取向也由(100)逐渐向(002)转变;靶基距较小时,AlN压电薄膜与基底结合得更牢固,而压电薄膜与基底结合的紧密程度对多层膜声表面波(SAW)器件性能优劣的影响至关重要。 相似文献
14.
利用中频磁控反应溅射技术在玻璃衬底上制备氮化铝(AlN)薄膜,并经退火处理.利用X-衍射和原子力显微镜分析了AlN薄膜的结构及表面形貌.结果表明,衬底温度和退火工艺对AlN薄膜的结构和表面形貌有重要影响.研究表明,衬底温度为230 ℃时,AlN薄膜的表面粗糙度最小,退火能减小AlN薄膜表面粗糙度. 相似文献
15.
Pulsed laser deposition and processing of wide band gap semiconductors and related materials 总被引:1,自引:0,他引:1
R. D. Vispute S. Choopun R. Enck A. Patel V. Talyansky R. P. Sharma T. Venkatesan W. L. Sarney L. Salamancariba S. N. Andronescu A. A. Iliadis K. A. Jones 《Journal of Electronic Materials》1999,28(3):275-286
The present work describes the novel, relatively simple, and efficient technique of pulsed laser deposition for rapid prototyping
of thin films and multi-layer heterostructures of wide band gap semiconductors and related materials. In this method, a KrF
pulsed excimer laser is used for ablation of polycrystalline, stoichiometric targets of wide band gap materials. Upon laser
absorption by the target surface, a strong plasm a plume is produced which then condenses onto the substrate, kept at a suitable
distance from the target surface. We have optimized the processing parameters such as laser fluence, substrate temperature,
background gas pressure, target to substrate distance, and pulse repetition rate for the growth of high quality crstalline
thin films and heterostructures. The films have been characterized by x-ray diffraction, Rutherford backscattering and ion
channeling spectrometry, high resolution transmission electron microscopy, atomic force microscopy, ultraviolet (UV)-visible
spectroscopy, cathodoluminescence, and electrical transport measurements. We show that high quality AlN and GaN thin films
can be grown by pulsed laser deposition at relatively lower substrate temperatures (750–800°C) than those employed in metal
organic chemical vapor deposition (MOCVD), (1000–1100°C), an alternative growth method. The pulsed laser deposited GaN films
(∼0.5 μm thick), grown on AlN buffered sapphire (0001), shows an x-ray diffraction rocking curve full width at half maximum
(FWHM) of 5–7 arc-min. The ion channeling minimum yield in the surface region for AlN and GaN is ∼3%, indicating a high degree
of crystallinity. The optical band gap for AlN and GaN is found to be 6.2 and 3.4 eV, respectively. These epitaxial films
are shiny, and the surface root mean square roughness is ∼5–15 nm. The electrical resistivity of the GaN films is in the range
of 10−2–102 Θ-cm with a mobility in excess of 80 cm2V−1s−1 and a carrier concentration of 1017–1019 cm−3, depending upon the buffer layers and growth conditions. We have also demonstrated the application of the pulsed laser deposition
technique for integration of technologically important materials with the III–V nitrides. The examples include pulsed laser
deposition of ZnO/GaN heterostructures for UV-blue lasers and epitaxial growth of TiN on GaN and SiC for low resistance ohmic
contact metallization. Employing the pulsed laser, we also demonstrate a dry etching process for GaN and AlN films. 相似文献
16.
金刚石基底上制备(002)AlN薄膜的研究 总被引:1,自引:1,他引:0
首先采用微波等离子体化学气相沉积(MPCVD)方法,在O2/H2/CH4混合气体气氛下利用大功率微波在(100)Si片上生长出了异质外延金刚石膜,X-射线衍射(XRD)、拉曼光谱和场发射扫描电子显微镜(FESEM)对薄膜的表征分析结果表明,制备的金刚石膜具有很高的金刚石相纯度,且晶粒排列紧密;继而采用射频磁控反应溅射法,在抛光的金刚石基底上成功制备了高C轴择优取向的氮化铝(AlN)薄膜,研究了不同的溅射气压、靶基距对AlN薄膜制备的影响,XRD检测结果表明,溅射气压低,靶基距短,有利于AlN(002)面择优取向,相反则更有利于AlN薄膜的(103)面和(102)面择优取向;研究了AlN薄膜在以N终止的金刚石基底和纯净金刚石基底两种表面状态上的生长机制,结果发现,以N终止的金刚石基底非常有利于AlN(002)面择优取向生长;从Al-N化学键的形成以及溅射粒子平均自由程的角度,探讨了其对AlN薄膜择优取向的影响。 相似文献
17.
GaN films have been grown at 1050 °C on porous silicon (PS) substrates by metalorganic vapour phase epitaxy. The annealing phase of PS has been studied in temperature range from 300 to 1000 °C during 10 min under a mixture of ammonia (NH3) and hydrogen (H2). The PS samples were characterized after annealing by scanning electronic microscope (SEM). We observed that the annealing under the GaN growth conditions does not affect the porous structure.For the growth of the active GaN layer we used a thin AlN layer in order to improve wetting between GaN and PS/Si substrate. The growth of AlN and GaN films was controlled by laser-reflectometry. We estimated the porosity of PS samples from the evolution of the reflectivity signal during the AlN growth. The crystalline quality and surface morphology of GaN films were determined by X-ray diffraction and SEM, respectively. Preferential growth of hexagonal GaN with (0002) direction is observed and is clearly improved when the thickness of AlN layer increases. Epitaxial GaN layers were characterized by photoluminescence. 相似文献
18.
Juan Xiong Hao-Shuang Gu Wen Wu Ming-Zhe Hu Peng-Fei Du Hong Xie 《Journal of Electronic Materials》2011,40(7):1578-1583
AlN thin films are of continuing interest for excitation of acoustic waves in surface and bulk acoustic wave devices. We report
herein on preparation and characterization of c-axis inclined AlN films by a new method of rotating the substrate holder plate to different angles in an off-center system.
The microstructure of the c-axis inclined AlN films was investigated using x-ray diffraction, scanning electron microscopy, and transmission electron
microscopy. The analyses showed that polycrystalline AlN films with c-axis inclination of up to 12° could be obtained using the off-center system. Solidly mounted resonators based on the deposited
c-axis inclined and vertical AlN films were successfully realized. The frequency responses showed dual-mode resonance characteristics
located at 1.12 GHz and 1.87 GHz, corresponding to shear and longitudinal resonant modes, respectively. 相似文献
19.
AlN薄膜因其具有优异的物理化学性能而有着广阔的应用前景,采用反应磁控溅射法在低温条件下制备AlN薄膜是近些年科研工作的热点.采用直流磁控溅射法,于室温下通入不同流量的氮气在p型硅(100)和载玻片衬底上沉积了AlN薄膜.利用傅里叶变换红外(FTIR)光谱仪、X射线衍射仪(XRD)、扫描电子显微镜(SEM)和分光光度计等分析薄膜的组分、结构、形貌和光学性能.结果表明随着氮气流量的增加,AIN薄膜质量变好,N2流量为8 cma/min时制备的AlN薄膜为六方纤锌矿结构,在680 cm-1处具有明显的FTIR吸收峰,进一步说明成功制备了AlN薄膜.在300~ 900 nm的波长范围内,薄膜透过率最高可达94%;薄膜带隙随着氮气流量的增加而增大,最大带隙约为4.04 eV. 相似文献
20.
在平片蓝宝石衬底上,通过引入AlN缓冲层,优化成核层与粗糙层的生长条件,生长出了表面平整的GaN薄膜,晶体质量得到显著提升。通过引入AlN缓冲层,将X射线衍射(XRD)下样品(002)面的半高宽(FWHM)由232″降低至148″;通过减薄成核层厚度、提升粗糙层生长压力,将样品(102)面和(100)面的FWHM分别由243″和283″降低至169″和221″。研究了不同成核层和粗糙层的生长参数对GaN薄膜表面形貌的影响,随着(102)面和(100)面FWHM的降低,表面平整度亦得到改善,粗糙度由约3.8 nm下降到约1.6 nm。利用优化后的底层条件生长了高质量GaN薄膜,在3.5 A/mm^2电流密度下,与参考样品相比,制备出的LED样品的光输出功率由863 mW提升至942 mW,提升了约9%。 相似文献