Rapid thermal chemical vapor deposition of in-situ boron doped polycrystalline SIxGe1-x

In-situ doped polycrystalline Si_xGe_1-x (x = 0.7) alloys were deposited by rapid thermal chemical vapor deposition (RTCVD) using the reactive gases SiH₂Cl₂, GeH₄ and B₂H₆ in a H₂ carrier gas. The depositions were performed at a total pressure of 4.0 Torr and at temperatures 600° C, 650° C and 700° C and different B₂H₆ flow rates. The conditions were chosen to achieve high doping levels in the deposited films. Our results indicate negligible effect of B₂H₆ flow on the deposition rate. The depositions follow an Arrhenius type behavior with an activation energy of 25 kcal/mole. Boron incorporation in the films was found to follow a simple kinetic model with higher boron levels at lower deposition rates and higher B₂H₆ flow rates. As-deposited resistivities as low as 2 mΩ-cm were obtained. Rapid thermal annealing (RTA) in the temperature range 800-1000° C was found to reduce the resistivity only marginally due to the high levels of boron activation achieved during the deposition process. The results indicate that polycrystalline Si_xGe_1-x films can be deposited by RTCVD with resistivities comparable to those reported for in-situ doped polysilicon.     

空气中^131I的取样和测量方法的研究

本文介绍一种气态和气载~(131)I 取样器。着重介绍了一种指数分布源的效率刻度方法,讨论了与取样有关的一些问题。     

硼预淀积对自组织生长Ge量子点尺寸分布的影响

研究了以不同B2H6流量预淀积硼对UHV/CVD自组织生长Ge量子点尺寸分布的影响。在适当的生长条件下,得到了尺寸分布很窄的均匀Ge量子点,用AFM对量子点的形貌进行观察,Ge量子点尺寸的涨落小于±3%,量子点的水平尺寸和高度分别为60nm和10nm,密度为8×109cm-2。实验结果表明,通过预淀积硼表面处理,可以得到尺寸分布很窄的量子点,以满足量子点光电器件方面应用的要求。     

Studies on the growth of CdTe on Si using ge interfacial layer in an organometallic vapor phase epitaxial system

Epitaxial CdTe layers were grown using organometallic vapor phase epitaxy on Si substrates with a Ge buffer layer. Ge layer was grown in the same reactor using germane gas and the reaction of germane gas with the native Si surface is studied in detail at low temperature. It is shown that germane gas can be used to “clean” the Si surface oxide prior to CdTe growth by first reducing the thin native oxide that may be present on Si. When Ge layer was grown on Si using germane gas, an induction period was observed before the continuous layer of Ge growth starts. This induction period is a function of the thickness of the native oxide present on Si and possible reasons for this behavior are outlined. Secondary ion mass spectrometry (SIMS) data show negligible outdiffusion and cross contamination of Ge in CdTe.     

Si_（1－x）Ge_x／Si定向耦合器的研制

在运用ＳｉＧｅ脊形波导单模条件和有效折射率法分析ＳｉＧｅ／Ｓｉ定向耦合器结构参数的基础上，采用分子束外延和各向异性腐蚀技术制备出Ｓｉ１－ｘＧｅｘ／Ｓｉ（ｘ＝０．０５）单模定向耦合器．在波长为１．３μｍ时，平均串音小于－１８．１ｄＢ，输出功率耦合效率达到９８．１％     

只读式超分辨光盘的膜层设计和分析

超分辨技术是一种无需减小记录波长或增大数值孔径而提高存储密度的方法。Ge Sb Te是一种良好的相变光存储材料 ,在超分辨光盘中可作为掩膜。利用多层膜反射率的矩阵法计算了掩膜为Ge2 Sb2 Te5薄膜的超分辨只读式光盘的光学参数与各膜层厚度之间的关系 ,最后得到了较为理想的膜层厚度匹配。采用磁控溅射法制备了只读式超分辨光盘 ,测量了光盘的光学性质。     

Molten core fabrication of bismuth germanium oxide Bi4Ge3O12 crystalline core fibers

Optical fibers possessing a crystalline oxide core have significant potential for novel and useful electro‐ or nonlinear‐optic waveguides. Presently, however, their utility suffers from the slow speed and limited cladding materials afforded by conventional crystal‐fiber‐growth techniques. Described herein is the development of single phase bismuth germanium oxide crystalline core fibers using conventional glass fiber drawing. More specifically, fibers were fabricated and evaluated based on 2 embodiments of the molten core method. In a first approach, a Bi₄Ge₃O₁₂ single crystal was employed as the precursor and sleeved inside a borosilicate glass cladding. In the second approach, additional Bi₂O₃ was included along with the Bi₄Ge₃O₁₂ precursor single crystal. Glass clad fibers drawn from the precursor Bi₄Ge₃O₁₂ single crystal resulted in a polycrystalline core with various crystal morphologies (line‐like, dendrite‐like, and uniform grains) as will be discussed, while fibers drawn from the Bi₄Ge₃O₁₂ single crystal surrounded by Bi₂O₃ resulted in a more homogeneous microstructure. The eulytine crystal structure was crystallized using both approaches, with the formation of a secondary crystal phase using the second approach. More particularly, this work aims at showing that single phase and phase pure crystalline oxide core optical fibers can be achieved using conventional glass fiber draw processes, although further optimization is necessary for obtaining single crystalline core fibers.     

The Effect of the Addition of Re and Ge on the Properties of Pt/Al2O3

The effect of Re and Ge addition to Pt/Al₂O₃ was studied. Mono-, bi- and a trimetallic catalysts were prepared and characterized by TPR, XPS, TPO and by the n-pentane, cyclohexane (CH) and n-octane reactions. It was found that the trimetallic was the most active and stable catalyst and showed selectivities to aromatics and isomers very similar to the bimetallic germanium-based catalyst.     

辉光放电质谱仪测定超纯锗中23种痕量杂质元素

本文报导了一种用辉光放电质谱仪VG9000在无标准样品的情况下对超纯半导体材料锗中23种痕量杂质元素的直接而快速的定量测定方法。该方法具有10ppt量级的检测极限，是鉴定起统金属或半导体材料纯度（8N）的理想手段。     

Investigation on interracial and electrical properties of Ge MOS capacitor with different NH3-plasma treatment procedure

The effects of different NH3-plasma treatment procedures on interracial and electrical properties of Ge MOS capacitors with stacked gate dielectric of HfTiON/TaON were investigated.The NH3-plasma treatment was performed at different steps during fabrication of the stacked gate dielectric,i.e.before or after interlayer (TaON)deposition,or after deposition ofhigh-k dielectric (HfTiON).It was found that the excellent interface quality with an interface-state density of 4.79 × 1011 eV-1cm-2 and low gate leakage current (3.43 × 10-5 A/cm2 at Vg =1 V) could be achieved for the sample with NH3-plasma treatment directly on the Ge surface before TaON deposition.The involved mechanisms are attributed to the fact that the NH3-plasma can directly react with the Ge surface to form more Ge-N bonds,i.e.more GeOxNy,which effectively blocks the inter-diffusion of elements and suppresses the formation of unstable GeOx interfacial layer,and also passivates oxygen vacancies and dangling bonds near/at the interface due to more N incorporation and decomposed H atoms from the NH3-plasma.