改进的多孔硅生长模型和计算机模拟

基于多孔硅生长过程中阳极化电流,氢氟酸(HF)含量与多孔硅微结构的关系,提出一个改进的多孔硅生长模型,并进行了计算机模拟.该模型吸收了限制扩散模型的优点,同时考虑了F-与空穴的反应过程因素,利用该模型可以模拟出多孔硅形成过程中大电流条件下的电化学抛光现象.二维(100×100)点阵模拟结果与实验数据具有较好的匹配性,模拟得出的多孔硅的多孔度同实验数据相比较,误差不超过10%.     

Double threshold behaviour of I－V characteristics of CoSi2/Si Schottky contacts

The forward current－voltage (I－V) characteristics of polycrystalline CoSi₂/n-Si(100) Schottky contacts have been measured in a wide temperature range. At low temperatures (≤200K), a plateau-like section is observed in the I－V characteristics around 10^-4A·cm^-2. The current in the small bias region significantly exceeds that expected by the model based on thermionic emission (TE) and a Gaussian distribution of Schottky barrier height (SBH). Such a double threshold behaviour can be explained by the barrier height inhomogeneity, i.e. at low temperatures the current through some patches with low SBH dominates at small bias region. With increasing bias voltage, the Ohmic effect becomes important and the current through the whole junction area exceeds the patch current, thus resulting in a plateau-like section in the I－V curves at moderate bias. For the polycrystalline CoSi₂/Si contacts studied in this paper, the apparent ideality factor of the patch current is much larger than that calculated from the TE model taking the pinch-off effect into account. This suggests that the current flowing through these patches is of the tunnelling type, rather than the thermionic emission type. The experimental I－V characteristics can be fitted reasonably well in the whole temperature region using the model based on tunnelling and pinch-off.     

智能剥离——有竞争力的SOI制备新技术

ＳＯＩ（Ｓｉｌｉｃｏｎ－ｏｎ－Ｉｎｓｕｌａｔｏｒ）技术被认为是２１世纪的硅集成电路技术，近年来，国际上出现了一种引人注目的ＳＯＩ制备新技术－智能剥离（Ｓｍａｒｔｃｕｔ）技术，它的出现为解决ＳＯＩ技术中质量与价格的矛盾带来了新的希望，将会有力地堆动ＳＯＩ技术的进一步发展，文章简要回顾了目前存在的几种ＳＯＩ制备技术，并结合我们的工作重点介绍了智能剥离这种有竞争力的ＳＯＩ制备新技术。     

钛－镍－硅固相反应形成的镍硅化物/n-硅(100)接触的I-V-T研究

在不同退火温度下，有一薄层钛覆盖层的镍－硅经过固相反应生成了镍硅化物/n-硅(100)接触，研究了其在80K到室温的电流－电压（I-V）特性。低温I-V曲线在低偏压区的电流显著地比传统的热电子发射（TE）模型预计的要大。用基于Tung的夹断模型简化得到的双肖特基势垒模型分析了实测的I-V曲线，从中可以得到肖特基势垒不均匀性的量度。较高温度退火导致较大的势垒不均匀性，意味着硅化物薄膜均匀性的变坏。钛覆盖薄层可以稍微提高硅化镍的相转变温度，以及形成的一硅化镍的热稳定性。     

High Performance P-Channel Schottky Barrier MOSFETs with Self-Aligned PtSi Source／Drain on Thin Film SOI Substrate

P-channel metal-oxide-semiconductor field-effect transistors (MOSFETs) with PtSi Schottky barrier source/drain, high-k gate dielectric and metal gate electrode were fabricated on a thin p-type silicon-on-insulator (SOl) substrate using a simplified low temperature process. The device works on a fully-depleted accumulation-mode and has an excellent electrical performance. It reaches Ion/Ioff ratio of about 10^7, subthreshold swing of 65 m V/decade and saturation drain current of Ids = 8.8 μA/μm at |Vg - Vth| = |Vd| = 1V for devices with the channel length 4.0μm and the equivalent oxide thickness 2.Onto. Compared to the corresponding bulk-Si counterparts, SOI p-SBMOSFETs have smaller off-state current due to reduction of the PtSi/Si contact area.