高温快速热处理对硅中热施主的影响

研究了不同气氛(N2 、O2 、Ar)下高温快速热处理(RTP)对热施主形成和消除特性的影响.研究发现无论在何种气氛下进行高温RTP ,对热施主的形成均无影响.扩展电阻的分析结果表明,热施主在硅片纵向的分布是均匀的.根据高温RTP后硅片的空位特征,认为点缺陷对热施主的形成特性无影响.同时研究了高温RTP预处理对热施主消除特性的影响,发现氧气和氩气高温RTP的样品其生成的热施主经过6 5 0℃退火即可消除,和普通的热施主消除特性相同.而N2 气氛下高温RTP的样品,6 5 0℃退火后仍有部分施主存在,经95 0℃退火才能彻底消除,这可能是由于RTP处理中发生氮的内扩散     

Improved adaptive integral line-of-sight guidance law and adaptive fuzzy path following control for underactuated MSV

This paper presents an adaptive fuzzy path following control law based on an improved adaptive integral line-of-sight (IAILOS) guidance law for the underactuated marine surface vessel (MSV) exposed to the time-varying ocean currents and time-varying sideslip angle. Initially, the IAILOS guidance law is proposed which can not only calculate the desired yaw angle but also estimate the time-varying ocean currents and time-varying sideslip angle simultaneously. Furthermore, the adaptive fuzzy path following control law is established by combining with the estimator to cope with the MSV’s attitude tracking control and velocity tracing control problem via backstepping technique. Specifically, the dynamic uncertainties and unknown environment disturbances are compensated by the fuzzy logic system with fuzzy updating law based on estimation error rather than tracking error. Additionally, two high-order tracking differentiators (TDs) are designed to construct derivatives of virtual control vector and reduce computational complexity inherent in backstepping method. It is proved that the proposed adaptive fuzzy path following control law can drive the vessel to track the desired path and tracking error can converge to an arbitrarily small compact set, while guaranteeing all signals in the closed-loop control system are uniformly ultimately bounded. Finally, simulation results and comparisons are carried out to demonstrate the effectiveness of the proposed control approach.     

氢退火对掺氮硅中氧施主电学行为的影响

本文主要研究了在氢气下退火对掺氮直拉硅中热施主(TDs)和氮氧(N—0)复合体的影响。实验结果表明，在氢气下低温退火对热施主和N—O复合体的生成与在氩气下差不多。这说明低温氢退火注入到硅中的氢的量很少，不会对硅片的电阻率产生明显的影响。