硫酸蚀刻溶液中InP半导体之薄膜生长

利用X一射线衍射技术研究了InP半导体在H2SO4/H2O蚀刻溶液中之薄膜生长,分析P型InP（100）在酸性蚀刻溶液中表面氧化物的化学组成．实验中．一台12kW的铜旋转阳极x射线源用于保证高敏感度的表面型态分析．利用广角度衍射（WAD）,从一个基体氧化物的晶格组界面检测衍射线来分析蚀刻溶液H2SO4/H2O每个衍射线出现可能引起的反应物表面层反射光束的干涉图案,生成物为具有单晶结构的磷酸铟水合物（InP04-xH20）．观察到一组（nh,nk,n1）的广角度衍射中磷酸铟水舍物（InPO4·xH2O）相的反射峰,并且侦测到在每个反射光束的干扰振荡现象．利用感应电浆耦合离子发射光谱法测定溶液中的铟（In）和磷（P）成分,分析InP在不同浓度的H2S04／1-120溶液中的溶解速率．观察发现,在InP的氧化表面上存在混合成份的氧化物和单一成份生成物．借着ICP仪器分析测试在照光或暗室下,InP在H2SO4/H2O系统的溶解率差异几乎是不可分辨的．藉由X射线结果对比JCPDS卡标准化合物中的数据．可获得酸性溶液蚀刻反应中各种表面氧化物的结构特点和反应现象．     

A satellite clock error correction method in the wide area differential system

Based on the deep analysis of the wide area differential principle on the separation of satellite ephemeris errors and clock errors, the similarities and differences between the absolute separation of satellite ephemeris errors under time synchronization among the differential stations and relative separation of them under no time synchronization among them are analyzed. A one-station correction method of satellite clock errors including the 1st and the 2nd step correction is given under no time synchronization among these secondary stations, and the backward inference algorithm of the second correction of satellite clock errors is proposed. Through simulation analysis, satellite time service accuracy with code phase measurement can reach 5―7 ns, and that with carrier phase smoothing pseudo-range can reach 1―3 ns.