Arsenic and phosphorus codiffusion during silicon microelectronic processes

Arsenic (As) and phosphorus (P) implantations are concurrently used to create the n-zones of recent microelectronic device pn-junctions. We studied the As-P codiffusion effect on the junction depths during the dopant activation process. As diffusion is accelerated during codiffusion. The acceleration magnitude depends on As concentration and varies during annealing time. Contrasting with usual transient-enhanced-diffusion phenomena, a time delay can be observed before As diffusion acceleration occurs. P diffusion shows no specific modification due to codiffusion. Its diffusion behavior can be understood considering the usual Fermi level and electrical effects linked to the time evolution of the two dopant distributions. The behavior of As during codiffusion is discussed using finite element simulations.     

可锻铸铁防灰口孕育剂的研究

试验得到一种防灰口作用强的含Bi、Pb、Sb的可锻铸铁孕育剂。考核了该孕育剂的衰退特性及其对退火过程,机械性能的影响。     

影响退火钢板表层Mn析聚的因素及提高2030钢板抗锈蚀能力的对策

从2030与1420两冷轧单元工况上的差异出发,考察了2030CAPL和2030BAF中影响Mn等易氧化元素在钢板表面富集的因素.结果表明,退火温度、退火时间、退火前清洗介质中含Si与否、钢卷冷轧时的变形量等对Mn等的析聚有较大的影响;宝钢2030冷轧板表面Mn等元素的过度析聚也归因于退火温度(过高)、退火时间(过长)、CAPL退火前清洗介质中含有Si、钢卷冷轧时的变形量与退火温度时间的不完全匹配等的共同作用.考虑到2030冷轧单元对这些关键因素进行严格地控制和匹配较为困难,提出了"退火后轻微酸洗处理"的提高2030冷轧板抗锈蚀能力的措施.     

柳钢冷轧板带退火工艺和设备选择的探讨

介绍冷轧板带退火工艺的特点，探讨柳钢冷轧板带退火的设备选择。     

“模拟退火”在全局最优化中的应用和改进

电信网优化问题经合理简化可转换为四维整数区域上的全局最优化问题.但该问题的费用函数是极端‘病态’的,采用基本的‘模拟退火’算法效年低,解的稳定性也不够满意.本文针对基本 SA 算法的弱点探讨了几种改进方法,使算法效率和解的稳定性都有所改善.     

一种用于GSM系统的神经网络均衡器

在泛欧GSM移动通信系统中，由于存在码间干扰，必须采用信道均衡技术。常用的最大似然序列估计(MLSE)均衡器采用维特比算法(VA)，它只能用于具有较小时延扩展的信道。本文给出了一种适用于GSM系统的部分连接神经网络均衡器．其复杂度与信道的时延扩展成正比．特别适用于具有较大时延扩展的恶劣信道。为了消豫神经网络局部极小点引起的性能恶化．我们采用了均场退火技术。本文提出的均衡器既适于用模拟集成电路实现．又适于用数字集成电路实现。计算机仿真表明本文的方法具有比最常用的16状态和32状态VA更好的性能。     

Ion implantation of semi—insulating InP materials

The methods for protecting InP surface against degradation during annealing,including encapsulant and encpsulant-free techniques;rapid thermal an-nealing of InP implanted layers;implanted ion species and some profiles of typical dopants,etc.,they are all the key techniques concerning ion implantation into se-mi-insulating InP,and have been reviewed synthetically as well.     

Rapid thermal annealing effects on the photoluminescence properties of molecular beam epitaxy-grown GaIn(N)As quantum wells with Ga(N)As spacers and barriers

This article describes the effects of rapid thermal annealing (RTA) on the photoluminescence (PL) emission from a series of GaIn(N)As quantum wells. Indium compositions of both 20% and 32% were examined with nominal N compositions of 1% or 2%. The N location was varied within our quantum structure, which can be divided into three regions: (1) quantum well, (2) Ga(N)As spacer layers at the barrier-to-well interface and well-to-barrier interface, and (3) barriers surrounding each quantum well. Eight combinations of samples were examined with varying In content, Ga(N)As spacer layer thickness, N content, and N location in the structure. In the best cases, the presence of these Ga(N)As spacer layers improves the PL properties, due to annealing, with a reduction in the emission wavelength blueshift by ～400 Å, a reduction of the decrease in the full-width at half-maximum (FWHM) by ～5 meV, and a threefold reduction of the increase in integrated intensity. It was also observed that relocating N from the quantum wells to the barriers produces a comparable emission wavelength both before and after annealing. Our results further show that the composition of incorporated N in the material is most influential during the stages of RTA in which relatively small amounts of thermal energy is present from our lower annealing times and temperatures. Hence, we believe a low thermal-energy anneal is responsible for the recovery of the plasma-related crystal damage that was incurred during its growth. However, the In composition in the quantum well is most influential during the latter stages of thermal annealing, at increased times and temperatures, where the wavelength blueshift was roughly independent of the amount of incorporated N. As a result, our investigations into the effects of RTA on the PL properties support other reports that suggest the wavelength blueshift is not due to N diffusion.     

自适应分区段混合粒子群优化算法

该算法先利用Christos贪心算法将整个搜索区域进行自适应分区段,在每一区段内搜索出最优位置,然后将各区段的最优位置组成一新微粒群,继续搜索全局最优位置。而在每个区段中,又将模拟退火算法引入到粒子群优化(PSO)之中,通过Boltzmann机制选择每一区段中局部极值,使新算法在不同阶段兼顾对多样性和收敛速度的不同要求。与其他混合PSO算法相比,仿真实验表明,新算法具有较高的解精度,能较好地解决过早收敛问题。     

离子辐照后4H-SiC晶体退火前后的光谱研究

分析了高能pb27 辐照预注入12C 的和未预注入12C 4H-SiC样品在,退火前后傅立叶变换红外光谱和拉曼散射光谱的变化.从傅立叶变换红外光谱可以知道,900℃以上的退火使损伤层发生显著恢复;在拉曼散射光谱中可以看到1200℃退火后有石墨相的存在.实验结果说明,高温退火有利于损伤的恢复,使注入到碳化硅中的碳原子发生聚集并引起相变.