光诱导化学汽相淀积非晶硅薄膜及其在太阳电池中的应用

本文较系统地评述了光诱导化学汽相淀积(LCVD)技术淀积非晶硅薄膜的开发现状,主要介绍了LCVD淀积非晶硅薄膜 的机理.评价了LCVD淀积非晶硅薄膜的电学和光学特性,最后介绍了这种薄在制备晶硅太阳电池方面的应用.     

Deposition of High Purity Parylene- F Using Low Pressure Low Temperature Chemical Vapor Deposition

Parylene-F, poly(tetrafluoro-para-xylylene) (PA-F), has potential applications in microelectronics because of its high thermal stability and low dielectric constant. We found that a new precursor, 1,4-bis(trifluoromethyl) benzene (TFB) with a trace presence of α,α′-dibromo-α,α,α′,α′-tetrafluoro-p-xylene (DBX), can be used to produce PA-F films. PA-F films from this precursor are produced using a reaction line and a conventional deposition system. This process is simpler than previously reported processes and produces PA-F films with less impurities. The dielectric constant of the PA-F films produced by this process is 2.25 ± 0.05 at 1 MHz. The deposition process and the material properties of the PA-F films produced are presented.     

热丝化学气相沉积法低温制备纳米晶态碳化硅薄膜

采用热丝化学气相沉积(HFCVD)技术以甲烷(CH4)和硅烷(SiH4)作为源反应气体在Si(111)衬底上合成了纳米晶态SiC薄膜。通过X射线衍射(XRD)、扫描电镜(SEM)、高分辨透射电镜(HRTEM)以及光致发光(PL)检测技术对薄膜的晶体结构、表面形貌和PL特性进行了分析和表征。结果表明，在较低的衬底温度下所沉积的薄膜是由镶嵌于非晶SiC网络中的晶态纳米SiC构成。纳米晶粒平均尺寸约为6nm。室温下用HeCr激光激发样品，观到薄膜发出波长位于400～550nm范围内可见光辐射。     

SiC薄膜的化学汽相沉积及其研究进展

介绍了SiC薄膜的一种主要制备方法———化学汽相沉积(CVD)法制备SiC薄膜的近年研究进展,并对所制备薄膜的结构特征与物理性质进行了简要评述。     

化学气相沉积光学级金刚石薄膜的研究进展

化学气相沉积（CVD））金刚石薄膜优异的光学性能在近几年得到了广泛的重视,关于它的研究也在近几年取得了较大的突破。综述了CVD金刚石薄膜的光学性能,着重从成核、生长和后期处理三个方面对光学级CVD金刚石薄膜的制备进行了讨论,并对今后的研究作了展望。     

蓝宝石衬底上AlGaN外延材料的低压MOCVD生长

采用低温AlN成核层在1180℃温度下在(0001)蓝宝石衬底上用低压MOCVD设备生长了AlGaN外延层.Al组分高达0.6、厚度大于1μm的AlGaN外延层表面光亮,晶体质量较好,(0002)X射线衍射回摆曲线半峰宽FWHM为853弧秒.当反应室气压从5×103Pa降到2×103Pa后, AlGaN 外延层的生长速率和固相Al组分都显著提高.     

Large-Scale Synthesis of Graphene Films by Joule-Heating-Induced Chemical Vapor Deposition

We report large-area synthesis of few-layer graphene films by chemical vapor deposition (CVD) in a cold-wall reactor. The key feature of this method is that the catalytic metal layers on the SiO₂/Si substrates are self-heated to high growth temperature (900°C to 1000°C) by high-current Joule heating. Synthesis of high-quality graphene films, whose structural and electrical characteristics are comparable to those grown by hot-wall CVD systems, was confirmed by transmission electron microscopy images, Raman spectra, and current–voltage analysis. Optical transmittance spectra of the graphene films allowed us to estimate the number of graphene layers, which revealed that high-temperature exposure of Ni thin layers to a carbon precursor (CH₄) was critical in determining the number of graphene layers. In particular, exposure to CH₄ for 20 s produces very thin graphene films with an optical transmittance of 93%, corresponding to an average layer number of three and a sheet resistance of ~600 Ω/square.     

MOCVD法制备MgZnO合金薄膜

采用金属有机化学气相沉积方法在C面蓝宝石衬底上生长MgxZn1-xO合金薄膜.c轴取向的MgxZn1-xO薄膜在600～630℃温度下沉积. 通过X射线衍射和透射光谱研究了薄膜的结构和光学特性. 研究表明当x的取值小于等于0.39时，合金薄膜保持ZnO的六角形纤锌矿结构，没有观察到MgO分相，此时薄膜的能带宽度可以在3.3～3.95eV之间调节.     

Amorphous Silicon Films Prepared by Catalytic Chemical Vapor Deposition Method

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Zn-doped InGaAs Base Heterojunction Bipolar Transistors Grown by Low Pressure Metal Organic Chemical Vapor Deposition

High performance InP/InGaAs heterojunction bipolar transistors(HBTs) have been widely used in high-speed electronic devices and optoelectronic integrated circuits. InP-based HBTs were fabricated by low pressure metal organic chemical vapor deposition(MOCVD) and wet chemical etching. The sub-collector and collector were grown at 655 ℃ and other layers at 550 ℃. To suppress the Zn out-diffusion in HBT, base layer was grown with a 16-minute growth interruption. Fabricated HBTs with emitter size of 2.5×20 μm2 showed current gain of 70～90, breakdown voltage(BVCE0)＞2 V, cut-off frequency(fT) of 60 GHz and the maximum relaxation frequency(fMAX) of 70 GHz.     

等离子增强化学气相沉积法制备Si-C-H薄膜

以SiH4和CH4为气源,在不同的工艺条件下用增强化学气相沉积(PECVD)方法制备了一系列Si-C-H薄膜,并对薄膜的结构和性能进行了一系列测试分析,研究了薄膜的结构性能特点以及CH4/SiH4比和射频功率等工艺参数对薄膜结构和性能的影响。发现薄膜中主要形成的是嵌有Si晶粒的非晶态SiC结构,H原子主要以C-H键形式存在。高的射频功率和CH4/SiH4比均有利于Si-C的形成,而较低的CH4/SiH4比可以提高薄膜的晶态率。薄膜的电阻率随着CH4/SiH4比的增大而增大,随着射频功率的增大而减小。