Correlation between chemical and electrical profiles in Si+, Se+ and S+ implanted bulk and epitaxial GaAs

We compare the chemical profiles of Cr, Mn, Si and Se with the electron concentration profiles in Si, Se and S implanted semi-insulating Cr-O doped bulk GaAs substrates and undoped VPE buffer layers annealed with and without a SiO₂ encapsulant in a H₂-As₄ atmosphere. A higher activation efficiency in the net electron concentration and the gateless saturated channel current is measured for SiO₂ encapsulated wafers annealed under arsine overpressure than for capless annealed ones using Cr-O doped bulk GaAs substrates. On the other hand, the net donor concentration peak is higher for implanted buffer epi layers capless annealed under arsine overpressure than for SiO₂ encapsulated ones. Secondary ion mass spectrometry (SIMS) studies of the Cr decoration of the implant damage indicate that the damage from the 100 keV Si implant anneals out at 840°C while a temperature of 900°C is required to anneal out the 260 keV Se implant damage. An explanation of these differences is provided using an impurity redistribution model and charge neutrality considerations. Excellent Hall electron mobilities at liquid nitrogen temperature of 5400–9200 cm²/V-sec are measured for Si-implanted buffer epi substrates.     

碘液吸收砷化氢砷锑钼蓝分光光度法测定锡精矿中砷

采用盐酸-氯酸钾消解锡精矿试样,对锌还原碘吸收液吸收砷化氢砷锑钼蓝分光光度法测定锡精矿中砷的方法进行了研究。对试剂影响、共存元素干扰、分离及掩蔽进行了试验。方法的相对标准偏差在1．93％-6．99％之间,加标回收率在93．3％-105．7％之间,结果稳定,重现性好,满足锡精矿中砷的测定。     

砷化氢析出电势的探讨

据热力学参数,计算得到砷酸、亚砷酸、单的出砷化氢的标准平衡电势值分别为０．１４４Ｖ,０．００５Ｖ,－０．２３８Ｖ。在铜电解液净化工序中,砷酸优先于亚砷酸析出砷化氢,当阴极电势足够负时,帮人同放电析出砷化氢。计算结果与实测结果基本吻合,均表明砷化氢析出的标准平衡电势值正于－０．６０８Ｖ。在铜妆液工序中,采用控制阴极电势脱部胂电积法,能有效抑制砷化氢的析出。     

DBS—偶氮胂直接光度法测定粮食中稀土元素含量

鉴于稀土在农业上的广泛应用，本文作者提出：不经分离，直接光度法测定粮食中的稀土含昊ＰＨ＝３的酸性介质中，ＤＢＳ－偶氮胂与粮食中的稀土元素生成稳定的蓝紫色络合物，其摩尔吸光系数ε＝１．０６－１．２５×１０＾５升．摩尔＾－１，厘米＾－１，最大吸收波长为６２９－６４１ｎｍ，线性范围远远超过测定要求，在０－２５μｇ∑ＲｅｘＯｙ／２５ｍＬ的范围内符合比尔定律。本法于粮食中稀土含量的测定，可得满意结果。     

某含砷锑金矿石选矿综合回收试验研究

某含砷难处理锑金矿矿石采用混汞─浮选 (其中精尾 2不返回系统 )的工艺流程 ,浮选时使用亚硫酸钠作为降砷的抑制剂 ,使金、锑有用矿物得以充分综合回收。     

A kinetic model for tris(dimethylamino) arsine decomposition on GaAs(100) surfaces

In this paper, we outline the detailed arguments involved in developing a kinetic model describing surface pyrolysis of tris(dimethylamino) arsine (TDMAAs) on a GaAs(100) surface. Two decomposition pathways of TDMAAs on GaAs(100) are assumed: simple scission of the arsenic and nitrogen bond and surface β-hydrogen transfer reaction. The pre-exponential factor for the scission of the parent is assumed to be the largest among the species going through the scission pathway. Removal of the last dimethylamino ligand is assumed to be essentially the rate-limiting step of the overall decomposition of TDMAAs. The reaction steps and constraints so constructed enable us to derive kinetic parameters of reasonable values from temperature-programmed desorption data in literature. Computer simulations based on the model reproduce well the behavior of data in literature of desorption products from a heated GaAs(100) surface exposed to TDMAAs inside a vacuum chamber.     

我国超纯砷烷产业化生产技术研究

砷烷是电子气体中用途十分广泛,技术难度非常大的烷类气体,它是一个国家电子气先进与否的重要标志。超纯砷烷的产业化技术,涉及到砷烷的合成、净化、分析检测等诸多专业,为发展我国IC产业,尽快开展超纯砷烷产业化技术研究意义重大。     

氢化物发生原子荧光法测中毒检材中砷

本文研究了用氢化物发生原子荧光法测中毒检材中砷含量。本方法是将中毒检材进行有机质的破坏,使检材中砷全部还原为三价砷,在盐酸介质中,以硼氢化钾作还原剂,将三价砷转化为砷化氢。以高纯氩气作为载气将砷化氢从母液中分离,并导入石英炉原子化器中原子化。以砷特种空心阴极灯作激发光源,激发砷原子发出荧光,荧光强度值在一定范围内与砷的含量成正比。本方法灵敏度高,精密度好,检出限为0.0550μg/L。     

2016:中国气体

对2016年中国气体尤其是电子气体的发展进行了回顾。经过危机的洗礼,我国气体逆流而上,在某些关键性的气体品种上取得了可喜的业绩,实现了产能与质量的双飞跃,经过多年的努力,我国在电子特气领域的空白不断在填补,和国外发达国家的差距也不断在缩小。同时我们也要充分认识到在创先方面仍要做大量细致的工作,只有成为科技的跟随者成为领跑者我们才能成为气体的强国。     

高纯砷烷的合成与开发进展

砷化氢(AsH3)是一种重要的电子特气,它主要用于N型半导体的掺杂、离子注入、化学气相沉积(CVD)等。AsH3的工业合成主要有化学合成法和电解合成法2种,后者可在恒定浓度条件下制备AsH3。为满足电子工业所需的高纯度需求,需要对其进行精制。AsH3的精制方法主要包括吸附法、低温冷冻/精馏法、膜分离法等,它们均能满足各自不同的需求。同时介绍了AsH3的国内外经济概况和产品标准。