近红外激光诱导InP（100）表面蚀刻反应

采用超声氯分子束和时间分辨质谱研究了由１０６４ｎｍ近红外激光诱导ＩｎＰ（１００）表面蚀刻反应的产物质量分，入射Ｃｌ＿２分子束的平动能效应，激光能量密度和表面温度的影响，并讨论了反应机理。     

面向动态压力测量的微型压力传感器敏感结构

围绕微型压力传感器的动态性能对压力敏感结构设计进行了研究。结合有限元分析,掌握了压阻式微型压力传感器的膜片形状、膜厚、膜片平面尺寸对于固有频率、灵敏度的影响规律,明确了固有频率、灵敏度与敏感结构形状尺寸间的关系。结合研发实例,利用时域暂态有限元分析,研究了不同厚度的正方形敏感膜片对于正弦、阶跃压力载荷的动态响应情况。研究表明,较小的敏感膜片平面尺寸、较大的膜片厚度有利于获得高的固有频率,从而得到较宽的工作频带、较快的响应速度。     

压阻式压力传感器灵敏度与线性度的仿真方法

灵敏度和线性度是压力传感器最重要的两个性能指标。为了制作出能够满足实际应用需求的压力传感器,必需探索出一种压力传感器灵敏度和线性度的有效仿真方法。提供了一种基于对压阻式压力传感器薄膜表面应力的有限元分析(FEA)和路径积分的仿真方法,从而实现了在满量程范围内不同压力值下对传感器电压输出值的精确估计,在此基础上对压力传感器的灵敏度和线性度进行了有效仿真。实验结果验证了该方法的精确性:传感器样品的灵敏度测试值为42.462～44.460 mV/MPa,与仿真值之间的相对误差控制在3.3%以下,同时得到非线性低于0.16%的良好线性度以满足应用需求。     

Ar离子激光增强硅各向异性腐蚀速率的研究

研究了Ａｒ离子激光器与硅各向异性腐蚀技术相结合制造硅杯的方法。结果表明，激光照射能增强浸于ＫＯＨ溶液中硅的化学腐蚀速率，在入射光强为４．６Ｗ，ＫＯＨ溶液浓度为０．２２ｍｏｌ，温度为９０℃的条件下，得到＜１００＞硅的腐蚀速率为２１μｍ／ｍｉｎ，是无激光照射时硅各向异性腐蚀速率的多倍。进而讨论了硅在ＫＯＨ溶液中腐蚀速率对激光光强的依赖关系以及实验温度对腐蚀速率的影响问题。     

Piezoresistive characteristics of short-channel MOSFETs on (100)silicon

This paper demonstrates that the intrinsic piezoresistive response of the MOSFET channel is independent of length. The reported fall-off of the piezoresistive response of the transistor in short channel devices is shown to be the result of parasitic series resistance in the source of the transistor. At the same time, the experimental results demonstrate that the threshold voltage of the devices is essentially independent of stress. The results are verified for three independent processes     

反应离子刻蚀PMMA的各向异性刻蚀研究

研究目的是优化Ni掩膜PMMA RIE的刻蚀参数，在氧刻蚀气体中加入表面钝化性气体CHF3，以较快的刻蚀速率获得垂直的侧壁和最小的掩模钻蚀。采用平行板结构的反应离子刻蚀机刻蚀，研究了刻蚀气压，CHF3/O2比率和刻蚀温度对垂直、侧向刻蚀速率和PMMA微结构形貌的影响。试验表明：当CHF3含量大于50%或O2工作气压较低时，会显著影响RV/RL比，当RV/RL比大于8时，试样呈现出完全各向异性刻蚀。     

基于Au辅助化学刻蚀法实现低成本制备硅纳米线阵列

Au在Si表面的成膜质量对金属辅助化学刻蚀法制备硅纳米线至关重要.以Ti、Cr作为浸润层,可显著改善Au在硅表面的成岛趋势,获得优质的Au膜并大幅度减少Au的使用量.同时,针对加入Ti、Cr后对Au辅助化学刻蚀影响的研究表明,Cr在刻蚀液中是稳定的,因此阻碍了Au催化刻蚀反应,而Ti与反应溶液快速反应,不影响Au对Si衬底化学刻蚀的催化作用.基于以上工作,以PS球为模板沉积制备Ti/Au(3 nm/20 nm)优质膜,使用金属辅助化学刻蚀,制备了有序的Si纳米线阵列.     

Self-assembling Ge(Si)/Si(100) quantum dots

The morphological evolution of self-assembled epitaxial quantum dots on Si(100) is reviewed. This intensely investigated material system continues to provide fundamental insight guiding the growth of nanostructured electronic materials. Self-assembled quantum dots are faceted, three-dimensional islands which grow atop a planar wetting layer. Pure Ge growth at higher substrate temperatures results in narrower island size distributions but activates additional strain-relief mechanisms which will alter the optical and electronic properties of the dots. Optical and electrical characterization has shown that electrons and holes are confined to different regions of the dot. This results in a spatially indirect, type II recombination mechanism. Emerging device applications which exploit properties of these nanoscale Ge islands are discussed.     

Si上Si1-xGex:C 缓冲层的载流子分布

用化学气相淀积方法在Si(100)衬底上生长了Ge组分渐变的Si1-xGexC合金缓冲层.研究表明,较高温度下生长的Si1-xGexC缓冲层中Ge的平均含量较高,其晶体质量要优于较低温度下生长的外延薄膜.载流子浓度沿衬底至表面方向逐渐上升且Si1-xGexC缓冲层总体呈p型导电,存在一局域n型导电区,本文对其导电分布特性进行了分析研究.     

Si上Si1-xGex:C 缓冲层的载流子分布

用化学气相淀积方法在Si(100)衬底上生长了Ge组分渐变的Si1-xGex:C合金缓冲层.研究表明,较高温度下生长的Si1-xGex:C缓冲层中Ge的平均含量较高,其晶体质量要优于较低温度下生长的外延薄膜.载流子浓度沿衬底至表面方向逐渐上升且Si1-xGex:C缓冲层总体呈p型导电,存在一局域n型导电区,本文对其导电分布特性进行了分析研究.     

Si(100)和Si(111)衬底上的同质分子束外延

用超高真空电子束蒸发系统进行了硅的同质分子束外延.发现采用适当的表面化学处理方法,然后在超高真空中加热,可以在较低温度下(800—814℃)获得清洁和平整的有序表面.Si(100)和Si(111)的外延分别在520℃和714℃进行,外延膜的结构和电学特性良好.     

Self-Organization of Ge(Si) Nanoisland Groups on Pit-Patterned Si(100) Substrates

Semiconductors - Space-arranged arrays of pits on Si(001) substrates were prepared using electron-beam lithography and plasma chemical etching. The positions of pits were arrange to the square and...     

金属援助硅化学刻蚀法可控制备硅纳米线阵列

基于金属援助硅化学刻蚀机理,成功地发展了一种形貌可控地制备硅纳米线阵列的有效方法。在该方法中,通过银纳米颗粒催化层的微结构和硅化学刻蚀的时间来调控硅纳米线阵列的形貌。扫描电子显微镜(SEM)形貌表征的实验结果证实:硅纳米线阵列的孔隙率依赖银纳米颗粒催化层的微结构,硅纳米线阵列的高度依赖于硅的刻蚀时间。这种形貌可控地制备单晶硅纳米线阵列的方法简单、有效,可用于构筑硅纳米线光伏电池等各种硅基纳米电子器件。     

ZnO纳米棒与Si(111)和Si(100)衬底的外延关系(英文)

运用热蒸发技术在Si(111)和Si(100)基片上制备了ZnO纳米棒。SEM表征显示,ZnO纳米棒的直径约100nm,长度均匀,大约3μm;XRD表征发现ZnO纳米棒沿[0001]晶向择优生长。通过实验结果与理论分析得出:对于Si(111)基片上的样品,大部分ZnO纳米棒沿6个对称方向生长,而且与基片之间的夹角为54.7°,ZnO与Si(111)的外延关系为[0001]ZnO‖[114]Si,[0001]ZnO‖[4]Si,[0001]ZnO‖[141]Si,[0001]ZnO‖[4]Si,[0001]ZnO‖[411]Si,或[0001]ZnO‖[4]Si。对于Si(100)基片上的样品,大部分ZnO纳米棒沿4个对称方向生长,与基片之间的夹角为70.5°,其外延关系为[0001]ZnO‖[114]Si,[0001]ZnO‖[4]Si,[0001]ZnO‖[14]Si,或[0001]ZnO‖[14]Si。通过比较分析得出Si基片可以控制ZnO纳米棒的生长方向。     

SiGe quantum rings on the Si(100) surface

Results of experimental studies of forming SiGe nanometer-size rings on the Si(100) surface by the molecular-beam epitaxy method are presented. Detailed shapes and size distributions of the grown nanorings are studied by the atomic-force microscopy method. The elemental composition is determined by the Raman scattering method. The average germanium content in the nanorings was 37% for a forming temperature of 680°C. The obtained data on the geometry and composition of the produced nanostructures were used for calculations by the 6-band k × p-method of the energy spectrum and charge density distribution of hole states, localized on the SiGe quantum rings embedded in the Si-matrix. It is shown that the heterostructures with quantum SiGe rings are promising objects for creating devices that are capable of detecting electromagnetic radiation in terahertz and infrared wavelength ranges.     

Si(100)表面的TCS研究(英文)

Total current spectroscopy (TCS) is a newly developed method in detecting electronic properties of solid surfaces. In this work, a chemically cleaned Si(100) wafer was cleaned and annealed "by heating the sample up to about 850℃ in a UHV chamber with a pressure less than 1×10-7pa then the surface appeared a sharp 2×1 LEED pattern.In the TCS spectra both on cleaned and uncleaned surfaces, four peaks labeled A, B, C aad D appeared in 3.5, 6.4, 9.3, and 13.5eV, respectively, with respect to vacuum level. Among them peaks A,C,D remain unchanged while peak B is quite sensitive to gas absorption and the surface temperature, mainly by changing its intensity. The phenomena are explained by assuming that inelastic scattering of incident eletrons dominates the process. Peaks A,C, D were caused by interband transitions and peak B was attributed to the surface state. Further studies are in consideration.     

应变Si(100)态密度模型

应变Si技术是当前微电子领域研究发展的热点和重点,态密度是其材料的重要物理参量。基于应变Si/(100)Si1-xGex能带结构和载流子有效质量模型,获得了导带底电子和价带顶空穴态密度有效质量,并在此基础上建立了其导带底和价带顶附近态密度模型。该模型数据量化,可为应变Si/(100)Si1-xGex材料物理的理解及其他物理参量模型的建立奠定重要的理论基础。     

Growth of a Ge Layer on a Si/SiO2/Si(100) Structure by the Hot Wire Chemical Vapor Deposition

Semiconductors - Ge/Si layers are formed on Si/SiO2/Si(100) substrates and are investigated for different growth temperatures. The Si layer is grown by molecular-beam epitaxy, while the Ge layer is...     

Anisotropic Etching of SiO2 in High-Voltage Gas-Discharge Plasmas

An experiment is reported on anisotropic etching in a CF₄–O₂plasma produced by high-voltage gas discharge. The process is applied to SiO₂and is also effected on SiC, Si, C (diamond), and As₂S₃. It is shown that the etch rate is mainly dependent on the oxygen percentage, plasma parameters, and the wafer temperature. It is established that etch rate is maximal at oxygen percentages of 0.8–1.5%, discharge currents of 80–140 mA, and wafer temperatures of 390–440 K. The etching is found to be uniform within 1%.