共查询到18条相似文献,搜索用时 78 毫秒
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通过对比研究重掺砷直拉硅片和轻掺n型直拉硅片经过低温(450—800℃)和高温(1000℃)两步退火的氧沉淀行为,阐明了低温退火对重掺掺砷直拉硅片的氧沉淀形核的作用.研究指出:重掺砷硅片在450℃和650℃退火时的氧沉淀形核比在800℃退火时更显著,这与轻掺硅片的情况截然相反;此外,与轻掺硅片相比,重掺砷硅片在450℃和650℃退火时氧沉淀的形核得到增强,而在800℃退火时氧沉淀的形核受到抑制.分析认为,重掺砷硅片在450℃和650℃退火时会形成砷-空位-氧(As-V-O)复合体,它们促进了
关键词:
重掺砷直拉硅片
氧沉淀形核
低温退火 相似文献
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研究了直拉硅片从不同的温度线性升温(Ramping)到750℃,然后在750℃退火64 h过程中的氧沉淀行为. 结果表明,Ramping对硅片中氧沉淀的形成有明显的促进作用,且起始温度越低促进作用越强. 这是因为在Ramping处理中,低温(450—650℃)热处理阶段氧的扩散速率显著增强,促进了氧沉淀核心的形成,且较低的Ramping升温速率有利于氧沉淀核心的稳定和继续长大. 进一步的实验结果还表明,低起始温度的Ramping处理可应用于硅片的内吸杂工艺,能促进氧沉淀的生成提高硅片的内吸杂能力,减少热预
关键词:
直拉硅
氧沉淀
退火 相似文献
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研究了直拉硅片从不同的温度线性升温(Ramping)到750℃,然后在750℃退火64 h过程中的氧沉淀行为. 结果表明,Ramping对硅片中氧沉淀的形成有明显的促进作用,且起始温度越低促进作用越强. 这是因为在Ramping处理中,低温(450—650℃)热处理阶段氧的扩散速率显著增强,促进了氧沉淀核心的形成,且较低的Ramping升温速率有利于氧沉淀核心的稳定和继续长大. 进一步的实验结果还表明,低起始温度的Ramping处理可应用于硅片的内吸杂工艺,能促进氧沉淀的生成提高硅片的内吸杂能力,减少热预 相似文献
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研究了掺氮直拉硅单晶(NCZ)中氮在高温退火过程中对氧沉淀的影响.通过不同温度高温退 火后,测量氧沉淀的生成量和观察硅片体内微缺陷(BMD)密度与高温形核时间的变化关系 ,同时用透射电子显微镜(TEM)观察氧沉淀及相关缺陷的微观结构.实验结果表明高温退火后 氮对硅中氧沉淀形核有明显的促进作用,在相同退火条件下NCZ硅中BMD密度要远远高于相应 的普通直拉硅.这是由于氮在高温下与氧反应形成氮氧复合体(N-V-O)促进了氧沉淀的形核 ,而且TEM的结果表明氧沉淀的形态都是平板状,周围存在应力场.
关键词:
直拉硅
掺氮
氧沉淀 相似文献
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在等离子体增强化学气相沉积(PECVD)系统中,利用逐层淀积非晶硅(a-Si)和等离子体氧化相结合的方法制备二氧化硅(SiO2)介质层.电容电压(C-V)和电导电压(G-V)测量结果表明:利用该方法在低温(250 ℃)条件下制备的SiO2介质层均匀致密,其固定氧化物电荷和界面态密度分别为9×1011cm-2和2×1011cm-2·eV-1,击穿场强达4.6 MV/cm,与热氧化形成的SiO2介质层的性质相当.将该SiO2介质层作为控制氧化层应用在双势垒纳米硅(nc-Si)浮栅存储结构中,通过调节控制氧化层的厚度,有效阻止栅电极与nc-Si之间的电荷交换,延长存储时间,使存储性能得到明显改善.
关键词:
等离子体氧化
二氧化硅
纳米硅
控制氧化层 相似文献
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层错四面体是一种典型的三维空位型缺陷,广泛存在于受辐照后的面心立方金属材料中,对材料的力学性能有显著的影响.目前,关于层错四面体对辐照材料层裂行为的影响还缺乏深入系统的研究.本文使用分子动力学方法模拟了含有层错四面体的单晶铜在不同冲击速度下的层裂行为,对整个冲击过程中的自由表面速度及微结构演化等进行了深入的分析.研究发现,层错四面体在冲击波作用下会发生坍塌,并进一步诱导材料产生位错、层错等缺陷.在中低速度加载下,层错四面体坍塌引起的缺陷快速向周围扩展,为孔洞提供了更宽的形核区域,促进了孔洞的异质成核,造成材料层裂强度大幅度减小.当冲击速度较高时,层错四面体坍塌导致的局部缺陷对材料的层裂强度不再有明显影响. 相似文献
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本文采用分子动力学模拟方法研究了在拉伸载荷下,堆垛层错和温度对纳米多晶镁力学性能的影响,在模拟中,采用嵌入原子势描述镁原子之间的相互作用.计算结果表明:在纳米晶粒中引入堆垛层错能明显增强纳米多晶镁的屈服应力,但堆垛层错对纳米多晶镁杨氏模量的影响很小;温度为300.0K时,孪晶在晶粒交界附近形成,孪晶随着拉伸应变的增加而逐渐生长.当拉伸应变达到0.087时,一种基面与X—Y面成大约35°角且内部包含堆垛层错的新晶粒成核并快速增长.也就是说,孪晶和新晶粒的形成和繁殖是含堆垛层错的纳米多晶镁在300.0K温度下的主要变形机理.模拟结果也显示,当温度为10.0K时,位错的成核和滑移是含堆垛层错的纳米多晶镁拉伸变形的主要形式. 相似文献
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锯齿型单壁碳纳米管的广义层错能计算 总被引:1,自引:0,他引:1
基于密度泛函理论的第一性原理方法,计算了两种不同半径的锯齿型单壁碳纳米管以及单层石墨的广义层错能曲线。对小位移处广义层错能曲线进行斜率拟合所得切变模量与其它文献值一致。对三条广义层错能曲线的对比可知,锯齿型碳纳米管与单层石墨的广义层错能曲线相近,锯齿型单壁碳纳米管的曲率效应不明显。 相似文献
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利用金属有机化合物气相外延沉积技术在2inch(5.08cm)Si(111)图形衬底上生长了GaN外延薄膜,在Al组分渐变AlGaN缓冲层与GaN成核层之间引入了AlN插入层,研究了AlN插入层对GaN薄膜生长的影响。结果表明,随着AlN插入层厚度的增加,GaN外延膜(002)面与(102)面X射线衍射摇摆曲线半峰全宽明显变小,晶体质量变好,同时外延膜在放置过程中所产生的裂纹密度逐渐减小直至不产生裂纹。原因在于AlN插入层的厚度对GaN成核层的生长模式有明显影响,较厚的AlN插入层使GaN成核层倾向于岛状生长,造成后续生长的nGaN外延膜具有更多的侧向外延成分,从而降低了GaN外延膜中的位错密度,减少了GaN外延膜中的残余张应力。同时还提出了一种利用荧光显微镜观察黄带发光形貌来表征GaN成核层形貌和生长模式的新方法。 相似文献
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Y. A. Pusep A. D. Rodrigues L. J. Borrero‐Gonzlez L. N. Acquaroli R. Urteaga R. D. Arce R. R. Koropecki M. Tirado D. Comedi 《Journal of Raman spectroscopy : JRS》2011,42(6):1405-1407
Unexpectedly, the Fano resonance caused by the interference of continuum electron excitations with the longitudinal optical (LO) phonons was observed in random porous Si by Raman scattering. The analysis of the experimental data shows that the electron states trapped at the Si SiO2 interface dominate in the observed Raman scattering. The gap energy associated with the interface states was determined. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
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The low temperature specific heat of an n-type phosphorous doped silicon sample containing 5 × 1018 charge carriers/cm3 in zero magnetic field and in a magnetic field of 28.5 kGauss has been measured. Within the experimental accuracy of the experiments no magnetic contribution to the specific heat has been detected. This result is discussed in the light of recent E.S.R. experiments on the same impurity banded silicon sample. 相似文献
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系统研究了点缺陷对晶体硅中氧沉淀生成的影响,及点缺陷和氧沉淀对重掺硼直拉硅单晶p/p+外延片中铜沉淀的影响.样品先在不同的气氛下进行1250℃/60 s快速热处理,随后在750℃/8 h+1050℃/16 h常规热处理过程中引入铜沾污.通过腐蚀结合光学显微镜研究发现,以O2作为保护气氛时,p+衬底中的沉淀密度较小,以Ar和N2作为保护气氛时,重掺硼p+衬底中生成了高密度的沉淀,且在上述所有样品的外延层中均无缺陷生成.研究认为,以O2作为保护气时引入的自间隙硅原子(SiI)可以抑制沉淀的形成,而以Ar和N2作为保护气氛时引入的空位则会促进沉淀的生成,这是导致此差异的主要原因.另外,研究还发现,p/p+外延结构能很好地吸除硅片中的铜杂质,从而保持了外延层的洁净. 相似文献
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Recent interest in the study of stacking faults and non-basal slip in Mg alloys is partly based on the argument that these phenomena positively influence mechanical behaviour. Inspection of the published literature, however, reveals that there is a lack of fundamental information on the mechanisms that govern the formation of stacking faults, especially I1-type stacking faults (I1 faults). Moreover, controversial and sometimes contradictory mechanisms have been proposed concerning the interactions between stacking faults and dislocations. Therefore, we describe a fundamental transmission electron microscope investigation on Mg 2.5 at. % Y (Mg–2.5Y) processed via hot isostatic pressing (HIP) and extrusion at 623 K. In the as-HIPed Mg–2.5Y, many 〈c〉 and 〈a〉 dislocations, together with some 〈c + a〉 dislocations were documented, but no stacking faults were observed. In contrast, in the as-extruded Mg–2.5Y, a relatively high density of stacking faults and some non-basal dislocations were documented. Specifically, there were three different cases for the configurations of observed stacking faults. Case (I): pure I2 faults; Case (II): mixture of I1 faults and non-basal dislocations having 〈c〉 component, together with basal 〈a〉 dislocations; Case (III): mixture of predominant I2 faults and rare I1 faults, together with jog-like dislocation configuration. By comparing the differences in extended defect configurations, we propose three distinct stacking fault formation mechanisms for each case in the context of slip activity and point defect generation during extrusion. Furthermore, we discuss the role of stacking faults on deformation mechanisms in the context of dynamic interactions between stacking faults and non-basal slip. 相似文献
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Bond-centered muonium ( Mu(0)(BC)) has been observed in very heavily doped n-type Si:P. It exhibits a Curie-like electronic spin susceptibility which leads to a giant negative shift in the muon spin precession frequency. At high dopant levels, the Mu(0)(BC) hyperfine parameters, deduced from a model involving spin exchange with free carriers, are significantly reduced from those in intrinsic Si. This indicates that the spin density distribution for Mu(0)(BC) in metallic Si:P is altered significantly by charge screening effects, likely a general phenomenon for deep impurities in materials with high carrier concentrations. 相似文献
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Yutaka Ohno Yuki Tokumoto Hiroto Taneichi Ichiro Yonenaga Kensuke Togase Sigeto R. Nishitani 《Physica B: Condensed Matter》2012,407(15):3006-3008
The width of a stacking fault ribbon bound by a pair of partial dislocations in silicon crystals was unchanged when boron and gallium atoms of p-type dopant were agglomerated nearby the ribbon by annealing, even though the width increased when n-type dopant atoms were agglomerated as previously reported [Y. Ohno, Y. Tokumoto, I. Yonenaga, Thin Solid Films, accepted for publication]. The origin of the width-increase in n-type crystals was proposed as the reduction of the stacking fault energy, from 58±5 down to 46±5 mJ/m2, due to an electronic interaction between the ribbon and the n-type dopant atoms, and the interaction energy was estimated to be 0.15±0.05 eV. On the other hand, the interaction of p-type dopant atoms with stacking faults was not detected. 相似文献
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A. Castaldini A. Cavallini A. Poggi E. Susi 《Applied Physics A: Materials Science & Processing》1989,48(5):431-436
A spectroscopic analysis by the light-beam-induced-current technique has been carried out to study the electrical properties of stacking faults in Czochralski silicon subjected to internal gettering treatments. By changing the wavelength of the light beam probing the sample, we have obtained the depth profiling of the stacking fault electrical activity. Occurrence of minority carrier recombination and generation processes at some stacking faults, corresponding, respectively, to dark and bright levels in a grey-shade imaging, has been observed. The presence of fixed charges at the defect-silicon matrix interface is hypothesized as a possible cause of the observed images. 相似文献
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理论研究了平面电磁波通过n型重掺GaAs薄膜的透射谱.当GaAs薄膜两表面刻上亚波长的周期性沟槽结构时,透射谱在中红外波段出现了异常的透射增强现象.把这一现象归因于表面等离子体模式和波导模式的耦合.通过优化结构参数可以得到最大的透射效率.此外,发现随着掺杂浓度的升高,透射谱线中的透射峰逐渐向高频方向移动,最优化后透射峰值随掺杂浓度的升高而逐渐降低.这是由于掺杂浓度的改变,导致了不同的等离子体频率和电子碰撞频率,从而影响了激发模式和薄膜对电磁波的吸收.
关键词:
表面等离子体
掺杂半导体
增强透射
掺杂调制 相似文献