GeSi/Si Mach-Zehnder干涉型调制器的研制

基于ＧｅＳｉ合金的等离子体色散效应,研制了一种Ｍａｃｈ－Ｚｅｈｎｄｅｒ干涉型调制器,通过对其损耗和调制特征的测试得到：调制器对１．３μｍ光的插入损耗为６．５ｄＢ,最大调制深度达８５％,相应的π相移调制民压为０．９Ｖ,关断电流和调制区的注入电流密度分别为４０ｍＡ和０．９７ｋＡ／ｃｍ＾２。     

高温对GexSi1—x／Si

用ＧｅｘＳｉ１－ｘ／Ｓｉ亚稳材料在高温下制作了光波导，它的传输损耗为０．８ｄＢ／ｃｍ，比低温工艺的０．５ｄＢ／ｃｍ稍大。并发现ＧｅｘＳｉ１－ｘ／Ｓｉ材料的大量失配位错的一些有趣的现象。     

Mach—Zehnder型GaAs／GaAlAs行波光调制器的微波特性分析

提出利用n^ 重掺杂层的慢波效应研制Mach-Zehnder干涉型行波光调制器,并通过在相对介电常数εr中引入与电导率有关的虚部σ/ωε0,拓展了直线法对介质损耗的计算,文中指出在这种共面微带线中奇模和偶模的不同作用,重点分析和研究了器件行波电极的微波特性,从而设计出理论上可达46GHz带宽的高速光波导调制器。     

GexSi1—x等离子体色散效应及电光调制器

在研究了Ｓｉ的等离子体色散效应之后，我们预计ＧｅｘＳｉ１－ｘ也会有这一效应，理论分析和实践的结果都表明ＧｅｘＳｉ１－ｘ具有比Ｓｉ更强的等离子体色散效应。     

GexSi1—x／Si光波导及其器件的最新研究进展

综述了１９９４年以来国内外在ＧｅｘＳｉ１－ｘ／Ｓｉ光波导及其器件结构、工艺等方面的最新研究进展。     

载流子吸收对SOIMach-Zehnder干涉型电光调制器性能的影响

分析了载流子吸收对SOI材料制作的Y分支型Mach-Zehnder干涉型电光调制器/开关性能的影响,并提出了改进器件性能的一些措施.     

紧缩型SOI多模干涉光开关的设计

提出了一种新的紧缩型SOI多模干涉(MMI)光开关。开关由单模输入输出波导和MMI耦合器组成。通过在多模波导区域引入调制区,利用Si的等离子色散效应(PDE)改变调制区的折射率来实现开关动作。用FD-BPM方法对开关的工作原理和性能进行了模拟与分析。结果表明,光开关良好的综合性能,而整个开关的长度只有7mm。     

载流子吸收对SOIMach-Zehnder干涉型电光调制器性能的影响

分析了载流子吸收对SOI材料制作的Y分支型Mach-Zehnder干涉型电光调制器/开关性能的影响,并提出了改进器件性能的一些措施.     

GaAs／GaAlAs截止型光波导调制器的设计

利用近似解析方法，详细地讨论了金属覆盖层介质波导在截止点附近的模式传播特种和截止条件，并结合有效折射率方法讨论了脊高和脊宽对脊形波导截止条件的影响，设计了一种双层质结截止型强度调制器。     

Ge_(0.05)Si_(0.95)/Si脊形光波导的光场分析及设计

利用有效折射率法分析了Ge0.05Si0.95／Si脊形光波导的光场分布，得到了这种光波导在传输单模时内脊高b、外脊高h和脊宽W的合理取值，还为其它光波导器件的设计奠定了基础。     

高温对Ge_xSi_(1-x)/Si光波导及材料的影响

用ＧｅｘＳｉ１－ｘ／Ｓｉ亚稳材料在高温下制作了光波导，它的传输损耗为０．８ｄＢ／ｃｍ，比低温工艺的０．５ｄＢ／ｃｍ稍大。并发现ＧｅｘＳｉ１－ｘ／Ｓｉ材料的大量失配位错和一些有趣的现象。     

Research and Design of Ge0.6Si0.4／Si Strained—layer Superlattice Planar Optical Waveguide

Calculation shows that the refraction index of Ge0.6Si0.4/Si strained-layer superlattice n≈3.64,when Lw=9 nm and Lb=24 nm.An algorithm of numerical iteration for effective refraction index is emploted to obtain different effective refraction indexes at different thickness(L) .As a result, the thickness of Ge0.6Si0.4/Si strained-layer superlattice optical waveguide,L≤363 nm, can be determlned, which is very important for designing waveguide devices.An optical waveguidecan be madeinto a nanometer device by using Ge0.6Si0.4/Si strained-layer superlattice.     

1.55μmSi_(1-x)Ge_x/Si光开关与光探测器集成的分析及设计

对１．５５μｍ波长的Ｓｉ１－ｘＧｅｘ光波导开关和Ｓｉ１－ｘＧｅｘ／Ｓｉ红外探测器的集成结构进行了系统的理论分析和优化设计。设计结果为：（１）对Ｓｉ１－ｘＧｅｘ光开关，Ｇｅ含量ｘ＝０．０５，波导的内脊高、脊宽和腐蚀深度分别为３，８．５和２．６μｍ，分支角为５～６°。要实现对１．５５μｍ波长光的开关作用，ｐｎ＋结上所需加的正向偏压值应为０．９７Ｖ；（２）对Ｓｉ１－ｘＧｅｘ／Ｓｉ探测器，Ｇｅ含量ｘ＝０．５，探测器由２３个周期的６ｎｍＳｉ０．５Ｇｅ０．５和１７ｎｍＳｉ交替组成厚度为５５０ｎｍ，长度约为１．５～２ｍｍ的超晶格，内量子效率达８０％以上。     

Comparison of GexSi1—x Grown by UHV／CVD from Si2H6／GeH4 and SiH4／GeH4

Using double crystal X-rays diffraction (DCXRD) and atomic force microscopy (AFM), the results of Ge x Si 1- x grown by UHV/CVD from Si 2H 6 and SiH 4 are analyzed and compared. Adsorbates can migrate to the energy-favoring position due to the slow growth rate from SiH 4. In this case, a Si buffer that isolates the effect of substrate on epilayer could not be grown, which results in a pit penetrating into epilayer and buffer. The FWHM is 0.055° in DCXRD from SiH 4. The presence of diffraction fringes is an indication of an excellent crystalline quality. The roughness of the surface is improved if grown by Si 2H 6; however, the crystal quality of the Ge x Si 1- x material became worse than that from SiH 4 due to much larger growth rate from Si 2H 6. The content of Ge is obtained from DCXRD, which indicates the growth rate from Si 2H 6 is largest, then GeH 4, and that from SiH 4 is least.     

Effect on ion implanted germanium profile on the characteristics of Si/sub 1-x/Ge/sub x//Si heterojunction bipolar transistors

An optimum profile for Ge ion implantation in SiGe/Si heterojunction bipolar transistors is determined by using a two-dimensional simulator code for advanced semiconductor devices. The simulation code is based on a two-dimensional drift-diffusion model for heterostructure degenerate semiconductors with nonparabolicity included in the energy band structure. The model allows accurate simulations of carrier transport in short base devices. The simulation results indicate that for high current gain the Ge profile maximum must be close to the base-collector junction, and that the unavoidable tail of the implanted germanium in the collector region does not deteriorate the gain.<>     

Implementation of both high-hole and electron mobility in strained Si/strained Si/sub 1-y/Ge/sub y/ on relaxed Si/sub 1-x/Ge/sub x/ (x

Jongwan Jung Lee  M.L. Shaofeng Yu Fitzgerald  E.A. Antoniadis  D.A. 《Electron Device Letters, IEEE》2003,24(7):460-462

Elimination of dislocations in heteroepitaxial MBE and RTCVD Ge x Si1-x grown on patterned Si substrates

We have grown Ge _x Si_1-x (0 <x < 0.20,1000–3000Å thick) on small growth areas etched in the Si substrate. Layers were grown using both molecular beam epitaxy (MBE) at 550° C and rapid thermal chemical vapor deposition (RTCVD) at 900° C. Electron beam induced current images (EBIC) (as well as defect etches and transmission electron microscopy) show that 2800Å-thick, MBE Ge_0.19Si_0.81 on 70-μm-wide mesas have zerothreading and nearly zero misfit dislocations. The Ge_0.19Si{0.81} grown on unpatterned, large areas is heavily dislocated. It is also evident from the images that heterogeneous nucleation of misfit dislocations is dominant in this composition range. 1000Å-thick, RTCVD Ge_0.14Si_0.86 films deposited on 70 μm-wide mesas are also nearly dislocation-free as shown by EBIC, whereas unpatterned areas are more heavily dislocated. Thus, despite the high growth temperatures, only heterogeneous nucleation of misfit dislocations occurs and patterning is still effective. Photoluminescence spectra from arrays of GeSi on Si mesas show that even when the interface dislocation density on the mesas is high, growth on small areas results in a lower dislocation density than growth on large areas.