氧化铝模板法制备Ge纳米线

采用氧化铝模板法结合具有高真空背景的低压化学气相沉积技术制备出 Ge纳米线 .在氧化铝模板的背面喷金作为催化剂 ,合成了 Ge纳米线 .采用原子力显微镜、X射线衍射、透射电镜、能量散射谱等手段对 Ge纳米线进行了分析 .Ge纳米线的直径约为 30 nm,长度超过 6 0 0 nm.对 Ge纳米线的生长机理进行了探讨 .     

pnp型SiGe HBT的制备研究

从pnp型Si/SiGe HBT的能带结构出发，阐述pnp型Si/SiGe HBT的较大原理，采用MBE方法生长Si/Si1-xGex合金材料，并对Si/Si1-xGex合金材料的物理特性和异质结特性进行表征，在重庆固体电子研究所工艺线上，研制出了pnp型Si/SiGe HBT器件，器件参数为：Vcb0=9V,Vcc0=2.5V,Veb0=5V,β＝10。     

高剂量Ge离子注入直接形成nc-Ge的研究

报道了分别采用剂量为1e1 6 ,1e1 7,5e 1 7和1e1 8cm- 2的高剂量Ge离子注入,不需退火即可在Si O2中直接形成Ge纳米晶的新现象.采用掠入射X射线衍射和激光喇曼谱等实验手段对样品进行了物相分析.结果表明,高剂量Ge离子注入可在SiO2 薄膜中直接形成Ge纳米晶(nc- Ge) ;非晶态Ge向晶态Ge发生相变的阈值剂量约为1e1 7cm- 2 ,离子注入直接形成的nc- Ge内部具有较大压应力,随着注入剂量的提高,nc- Ge的尺寸和含量均有提高.对纳米晶形成机理的研究认为,在Ge离子注入剂量达到阈值,此时膜中Ge非晶态团簇浓度达到饱和甚至过饱和,新入射的     

光纤激光器的研究与发展

介绍光纤激光器的工作原理、分类以及为消除激射过程中的许多不利因素，提高光束质量而采取的技术措施，同时介绍近几年同内外光纤激光器的研究与发展。     

Dual-band infrared detectors made on high-quality HgCdTe epilayers grown by molecular beam epitaxy on CdZnTe or CdTe/Ge substrates

In this paper, we present all the successive steps for realizing dual-band infrared detectors operating in the mid-wavelength infrared (MWIR) band. High crystalline quality HgCdTe multilayer stacks have been grown by molecular beam epitaxy (MBE) on CdZnTe and CdTe/Ge substrates. Material characterization in the light of high-resolution x-ray diffraction (HRXRD) results and dislocation density measurements are exposed in detail. These characterizations show some striking differences between structures grown on the two kinds of substrates. Device processing and readout circuit for 128×128 focal-plane array (FPA) fabrication are described. The electro-optical characteristics of the devices show that devices grown on Ge match those grown on CdZnTe substrates in terms of responsivity, noise measurements, and operability.     

可见光LED的进展——超高亮度LED及应用(二)

可见光ＬＥＤ的进展——超高亮度ＬＥＤ及应用（二）张万生梁春广（电子工业部第十三研究所，石家庄，０５００５１）４超高亮度发光管的发展［９～１４］４．１ＩｎＧａＡｌＰＤＨＬＥＤ发光强度达到坎德拉级发光管的高亮度化一直是半导体材料和器件的前沿课题之一，超高...     

^68Ge—^68Ga发生器的研制—硅胶柱上^68Ge与Ga,Cu,Zn的分离

测量了硫酸介质中Ｇｅ在硅胶上的分配比及Ｇａ、Ｃｕ、Ｚｎ在硅胶上的吸附。研究了硫酸浓度、Ｇａ浓度及原始溶液中Ｇｅ载体量对Ｇｅ分配比的影响。实验结果表明：用１０ｍｍ×３０ｍｍ硅胶柱，上柱料液为５０ｍＬ０．４μｇ／ｍＬＧｅ－０．２８ｍｏｌ／ＬＧａ－９ｍｏｌ／ＬＨ２ＳＯ４溶液，淋洗液为３０ｍＬ９ｍｏｌ／ＬＨ２ＳＯ４，流速为０．８５ｍＬ／ｃｍ２·ｍｉｎ时，Ｇｅ的穿透率为０．３９％，Ｇａ、Ｃｕ、Ｚｎ的去污系数分别为１．８×１０６、５．０×１０６、２．６×１０６。     

Deposition,post-deposition annealing,and characterization of epitaxial Ge films grown on Si(100) by pyrolysis of GeH4

As a first step towards developing heterostructures such as GaAs/Ge/Si entirely by chemical vapor deposition, Ge films have been deposited on (100) Si by the pyrolysis of GeH₄. The best films are grown at 700° C and are planar and specular, with RBS minimum channeling yields of ≈4.0% (near the theoretical value) and defect densities of 1.3 x 10⁸ cm⁻². Variations of in-situ cleaning conditions, which affect the nature of the Si substrate surface, greatly affect the ability to get good epitaxial growth at 700° C. The majority of the defects found in the Ge films are extrinsic stacking faults, formed by dissociation of misfit and thermal expansion accommodation dislocations. The stacking fault density is not significantly reduced by post-deposition annealing, as is the case for the dislocations observed in MBE Ge films. It is suggested that lowering the CVD growth temperature through the use of high vacuum deposition equipment would result in dislocation defects like those of MBE films which could then be annealed more effectively than stacking faults. Films with defect densities equivalent to MBE Ge films (~2 x 10⁷ cm⁻²) could then probably be produced.     

LaNiO3 and Cu3Ge contacts to YBa2Cu3O7-x films

Metallization of high-T_c superconductors using low resistivity metal oxides and Cu-Ge alloys has been investigated on high quality pulsed laser deposited epitaxial YBa₂Cu₃O_7-x (YBCO) films. Epitaxial LaNiO₃ (LNO) thin films have been grown on YBCO films at 700°C using pulsed laser deposition. The specific resistivity of LNO was measured to be 50 μΩ-cm at 300K which decreases to 19 μΩ-cm at 100K indicating good metallicity of the LNO films. The contact resistance of LNO-YBCO thin film interface was found to be reasonably low (of the order of 10^-4Ω-cm² at 77K) which suggests that the interface formed between the two films is quite clean and LNO can emerge as a promising metal electrode-material to YBCO films. A preliminary investigation related to the compatibility of Cu₃Ge alloy as a contact metallization material to YBCO films is discussed. The usage of other oxide based low resistivity materials such as SrRuO₃ (SRO) and SrVO₃ (SVO) for metallization of high-T_c YBCO superconductor films is also discussed.     

Low resistance pd/ge ohmic contacts to epitaxially lifted-off n-type GaAs film

A low resistance PdGe nonalloyed ohmic contact has been successfully formed to epitaxially lifted-off n-type GaAs films. The contact is made by lifting off partially metallized n-type GaAs films using the epitaxial lift-off method and bonding them to metallized Si substrates by natural intermolecular Van Der Waals forces. Low temperature sintering (200°C) of this contact results in metallurgical bonding and formation of the ohmic contact. We have measured specific contact resistances of 5 × 10⁻⁵ Ω-cm₂ which is almost half the value obtained for pure Pd contacts. Germanium forms a degenerately doped heterojunction interfacial layer to GaAs. Our experimental results show that germanium diffuses to the interface and acts as a dopant layer to n-GaAs film surface. Therefore, for epitaxially lifted-off n-type GaAs films, PdGe is a low resistance ohmic metal contact to use.