共查询到16条相似文献,搜索用时 140 毫秒
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器件级同质外延CVD金刚石膜上的具有高击穿电压的铝肖特基二极管 总被引:1,自引:1,他引:0
用微波等离子体化学气相沉积方法合成高品质同质外延金刚石膜,并且用扫描电镜和阴极荧光分析法评价。为了得到高薄膜生长速率,把甲烷浓度设定在4%。薄膜上的生长丘的数量和大小依赖于生长条件。在本工作的样品中,未发现任何非外延晶粒。室温下的阴极荧光分光结果表明这种金刚石薄膜具有与自由励起子相关的谱峰。氢终端的膜表面制作的铝电极显示了P型整流特性。击穿电压高于380V。实验结果表明,阴极荧光分析法观测到的缺陷和电性能密切相关,并且可以在有室温边发射的金刚石表面上制作具有高击穿电压的整流电极。 相似文献
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氧碳比对MPCVD法同质外延单晶金刚石的影响 总被引:1,自引:0,他引:1
以Ib型(100)取向高温高压(HPHT)单晶金刚石为基底、H2-CH4-CO2混合气为反应气源,利用10kW、2.45GHz不锈钢谐振腔式微波等离子体化学气相沉积(MPCVD)装置进行金刚石同质外延生长。通过光学显微镜表征外延生长金刚石的表面形貌;Raman光谱表征金刚石的结晶质量;螺旋测微仪测厚再计算生长速率,着重探讨工艺因素中氧碳比对同质外延金刚石生长速率、表面形貌、金刚石结晶质量的影响。结果表明随着氧碳比的增加,金刚石生长模式由二维形核模式转变为台阶流模式,结晶质量提高,生长速率变慢;在微波功率7.8kW、CH4浓度(与H2的比例)8%、气压18kPa、基底温度1080℃条件下,氧碳比为0.8时,金刚石结晶质量好且生长速率高(达16μm/h)。反应气源中引入合适比例的CO2是获得高的生长速率同时有效改善同质外延单晶金刚石结晶质量的有效方法。 相似文献
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利用热灯丝CVD法在硅衬底上合成出了金刚石膜。金刚石膜的质量和电子性质由扫描电子显微镜、拉曼谱、阴极发光及霍尔系数测量来表征。实验结果表明,沉积条件对金刚石膜电子性质和质量有重要影响。载流子迁移率随甲烷浓度增加而减少,但场发射随其增加而增强。压阻效应随微缺陷增多而降低。异质外延金刚石膜压阻因子在室温下100微形变时为1200,但含有大量缺陷的多晶金刚石膜压阻因子低于200,这是由于薄膜中缺陷态密度增加,并依赖于膜结构的变化。 相似文献
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热丝法低温生长硅上单晶碳化硅薄膜 总被引:4,自引:0,他引:4
提出了热丝化学气相淀积法,在低温(600-750℃)下成功地生长出硅上单晶碳化硅薄膜,X光衍射谱、喇曼光谱证实了外延膜的单晶结构,光致发光测量证明外延SiC材料室温下可稳定发射可见光。 相似文献
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在微波等离子体化学气相沉积金刚石膜时,采用负偏压使氢和硼离子轰击金刚石膜表面。发现单纯的氢离子的轰击会导致表面刻蚀,可使(001)面颗粒尺寸增大,用扫描电镜(SEM)和阴极发射光谱(CL)分析了硼离子掺杂后[001]取向的金刚石膜表面,发现CL中A峰消失,表明薄膜中位错密度降低,首次发现CL谱中741.5nm峰和575nm到625nm宽峰明显下降,表明在金刚石膜中,中性空位和氮空位缺陷基本消失,利用小原子穿透理论解释了这个现象。 相似文献
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CVD金刚石薄膜取向生长研究现状 总被引:1,自引:0,他引:1
单晶衬底上外延生长金刚石薄膜一直是VCD金刚石技术领域的重要研究方向之一,近年来这方面的研究取得了长足的进步。回顾了金刚石取向膜的研究史,介绍了提高金刚石膜取向度的方法和目前对金刚石取向膜生长过程,生长机理研究取得的进展及金刚石取向膜具有独特优异性能的实验研究。 相似文献
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采用微波等离子体化学气相沉积(MPCVD)法成功地在多孔硅上沉积出均匀、致密的金刚石膜。光致发光测量表明,金刚石膜可以有效稳定多孔硅的发光波长和发光强度,具有明显的钝化效应。金刚石膜的这个特点再加上高硬度特性使金刚石膜成为多孔硅的一种潜在的钝化膜。 相似文献
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研究了p-型异质外延和同质金刚石膜的在不同温度和磁场下的磁阻,磁阻器件的结构为条形和圆盘形,实验结果表明磁阻强烈依赖于磁场、温度和样品的几何形状,圆盘结构的磁阻大于条形结构,条形结构的磁阻还取决于不同的长-宽比。利用F-S薄膜理论,计算磁场为5T时条形和圆盘结构的磁阻分别为0.38和0.74,讨论了霍耳效应对磁阻的影响。给出了形状效应的可能机制。 相似文献
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D. Zhang J.M. Bian F.W. Qin J. Wang L. Pan J.M. Zhao Y.Z. Bai G.T. Du 《Materials Research Bulletin》2011,46(10):1582-1585
GaN films with highly c-axis preferred orientation are deposited on free-standing thick diamond films by low temperature electron cyclotron resonance plasma enhanced metal organic chemical vapor deposition (ECR-PEMOCVD). The TMGa and N2 are applied as precursors of Ga and N, respectively. The quality of as-grown GaN films are systematically investigated as a function of deposition temperature by means of X-ray diffraction (XRD) analysis, Hall Effect measurement (HL), room temperature photoluminescence (PL) and atomic force microscopy (AFM). The results show that the dense and uniformed GaN films with highly c-axis preferred orientation are successfully achieved on free-standing diamond substrates under optimized deposition temperature of 400 °C, and the room temperature PL spectra of the optimized GaN film show a intense ultraviolet near band edge emission and a weak yellow luminescence. The obtained GaN/diamond structure has great potential for the development of high-power semiconductor devices due to its excellent heat dissipation nature. 相似文献
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L. M. Apa′tiga V. M. Castano F. Alba 《Journal of Materials Science: Materials in Electronics》1998,9(6):473-476
A study of the phosphorescence mechanisms in polycrystalline diamond films was carried out through their thermoluminescent (TL) vanishing glow response. The polycrystalline diamond films phosphoresced when kept at room or higher temperatures after being excited with a UV light source. The observed behaviour of shallow and deep traps during the phosphorescence process can be explained with a simple time-dependent model. The diamond film phosphorescence was induced by exciting with a UV light source of 4 W and 254 nm wavelength. The TL vanishing glow curves were integrated from room temperature to 350°C at a linear heating rate of 10°C s-1 in a N2 atmosphere. The optical response of the diamond films was studied by means of its luminescence spectra, showing a broad emission band centered around 500 nm. 相似文献
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Oxygen treatment effects on properties of MgO thin films grown on single-crystalline diamond (1 0 0)
Oxygen post-treatment effects on the electronic structure and electrical properties of MgO films grown on homoepitaxial single-crystalline (1 0 0) diamond have been studied. MgO films examined were deposited at room temperature (RT) using an electron beam evaporator and were subsequently either annealed at 573-773 K for 12 h in oxygen ambient or treated by O2 plasma for 10-40 min. RT resistivities remarkably increased after the O2 annealing and plasma treatment, indicating that the post treatments play an essential part on the formation and positioning of bandgap states. Cathodoluminescence (CL) spectra had a broad band feature in a wavelength region from 360 to 530 nm, which were decomposed to several peaks originating mainly from the oxygen-vacancy-related F and F+ centers and the interstitial vacancies of MgO film. A prominent rectifying behavior of I-V property was observed for a Au/MgO/p-diamond layered structure. Based on temperature dependences of the electrical properties in a temperature region from RT to 600 K, the electrical conduction mechanism in the MgO films is discussed in relation to polaron-related conduction as well as the ionic conduction. 相似文献