SELF-DIFFUSION IN IRON-50% COBALT ALLOY

用剩余强度法测定了Fe~(55)及Co~(60)在铁-钴(50％)合金中850--980℃α-区域内的自扩散系数,结果分别为 D_(Fe)=0.26 exp(—55,600/RT)厘米~2/秒, D_(Co)=14 exp(—65,000/RT)厘米~2/秒。 激活能测定数值与用准化学理论分析结果符合较好。     

Photoreflectance Spectroscopy for Study of Si/SiGe/Si Heterostructure

UHVCVD-grown Si/Si1- xGex/Si heterostructure was investigated by Photoreflectance spectroscopy (PR). The principle of PR used in semiconductor film was thoroughly described. According to the E1 transition energy in the Si1- xGex alloy, the Ge content in SiGe film with constant composition can be accurately characterized. In this study, determine the composition uniformity of larger diameter SiGe epiwafer by PR mapping technique was determined. These results show PR is very promising for Si1- xGex epilayer characterization with constant Ge content and can provide film measurements for production-worthy line monitor.     

Effect of Ion Dose on Growth of Relaxed SiGe Layer on Ion Implantation Si Substrate

Thin strain-relaxed Si0.8Ge0.2 films (57.6 nm) on the 30 keV Ar ion implantation Si substrates for different dose (1 × 1014, 5 × 1014, 3 × 1015 cm-2) were grown by ultra high vacuum chemical vapor deposition (UHVCVD) system.Rutherford backscattering/ion channeling (RBS/C), high resolution X-ray diffraction (HRXRD), Raman spectra as well as atomic force microscopy (AFM) were used to characterize these SiGe films. Investigations by RBS/C as well as HRXRD demonstrate that these thin Sio.8Geo.2 films could indeed epitaxially grow on the Ar ion implantation Si substrates. Under low dose ( 1 × 1014 cm-2) and medium dose (5 × 1014 cm-2) implantation conditions, the relaxation extents of SiGe films are 60.6% and 63.6%, respectively. However, high dose implantation (3 × 1015 cm-2) prompt the strain in epitaxial SiGe film to be close to full relaxation status (relaxation extent of 96.6% ). On the other hand, determinations of RBS/C also indicate the crystalline quality of SiGe film grown on high dose implantation Si substrate is nearly identical to that grown on low dose (1 × 1014 cm-2) implantation Si substrate.     

微波低噪声SiGe HBT的研制

利用3μm工艺条件制得SiGeHBT(HeterojunctionBipolarTransistor),器件的特征频率达到8GHz.600MHz工作频率下的最小噪声系数为1.04dB,相关功率增益为12.6dB,1GHz工作频率下的最小噪声系数为1.9dB,相关功率增益为9dB,器件在微波无线通信领域具有很大的应用前景     

Raman characterisation of stress in recrystallisedsilicon-on-insulator

Raman scattering measurements were carried out to characterise Si films deposited on SiO₂-coated Si substrates and recrystallised by a graphite strip heater or Ar⁺ ion laser. The frequency downshifts of the Raman peaks demonstrate that the Si films are under tensile stress. The crystallinity of the recrystallised films is also discussed     

熔区固液界面温度梯度的优化与再结晶SOI晶膜质量的提高

本文研究了多晶硅薄膜在红外溶区再结晶过程中溶化和固化前沿不同的推进行为，提出为了提高再结晶质量，熔区两则对所得到的辐射能流密度分布有不同的要求，据此提出了一种兼熔化和固化要求的不对称加热区熔再结晶技术、成功地制备了高质量的ＳＯＩ晶膜。     

全耗尽SOI MOSFET的阈电压的解析模型

本文在近似求解全耗尽ＳＯＩＭＯＳＦＥＴ所满足的二维泊松方程的基础上，建立了阈电压的解析模型。     

基于Z参数的微波晶体管高频噪声网络分析方法

For high-capacity wavelength division multiplexing(WDM) in optical fiber transmission systems, multi-wavelength light sources are needed to be operated at precisely-determined wavelength swith a fine separation of 0.8 or 1.6nm.Increasing efforts have been put into deve...     

基于Z参数的微波晶体管高频噪声网络分析方法

利用Z参数噪声网络等效电路的分析方法,得到了用器件Z参数表示的微波双极晶体管噪声参数的表达式,通过对微波低噪声双极晶体管的高频参数进行测试和分析,并把器件的网络参数和物理参数相结合,来对器件的最小噪声系数进行计算和分析.     

Ti-Si0.84Ge0.16和Ti-Si系统的温度特性研究

实验分别测量了Ti-Si0.84Ge0.16与Ti-Si系统在依次经历700℃及730~900℃两步退火后的方块电阻。对比结果表明,Ti的锗硅化物与Ti的硅化物具有不同的温度特性。造成这一差异的原因与Ge原子在高温下的行为有关。实验利用XRD,研究了Ti(SiGe)2从C49相到C54相的转变。物相分析结果显示,其相转变温度在760~800℃之间。结合实验结论,对采用Ti硅化物工艺的自对准SiGe HBT进行了退火温度的优化,其适合的高温退火温度为850℃左右。