SiCl_4-SiH_4-H_2混合源的硅外延生长

本文探讨了SiCl_4/SiH_4/H_2混合源常压和低压硅外延生长技术.实验结果表明,混合源兼有SiCl_4和SiH_4两者的优点,并在一定比例下具有SiH_2Cl_2源的特性.它能降低外延生长温度、调节淀积速率,改善淀积的均匀性和抑制自掺杂效应.因此它可适应多种器件的要求.     

新的硅外延生长法—两段外延生长技术

一、序言近年来,随着集成电路的发展和固体器件的高频化,要求硅外延片的生长层厚度要很薄,且在与基片的界面处杂质分布很徒。这样的片子,在高速变容二极管、双极集成电路、高频晶体管或以PIN二极管、碰撞雪崩渡越时间二极管等为代表的微波二极管的制作中更是不可缺少。这些器件一般是在具有高浓度杂质的硅基片上或在掺杂了高浓度杂质的区域上生长具有低浓度杂质的硅外延层上制作的。一般,硅外延生长是利用调节掺杂气体的浓度或流量来控制杂质浓度。可是,在具有高浓度杂质的基片上生长具有低     

利用引导层在硅上生长单晶外延硅化物层

本文介绍了一种外延硅化物的新颖的晶体生长技术,即在超高真空条件下利用硅化物引导薄层(<60)来确定随后的外延硅化物的取向。采用这种方法可以在(Ⅲ)硅晶面上生长A型取向或是B型取向的NiSi_2单晶膜;可在(100)Si晶面生长连续的NiSi_2单晶膜,其界面平整,厚度均匀。使用更厚引导层,用相同工艺能在(Ⅲ)Si晶面生长CoSi_2厚膜。     

用球形滚槽法测量硅外延层的厚度

引言过去在测量外延层或扩散层的厚度时,曾采用过磨角法、秤量法、红外线反射法等方法。这些方法各有其优点,但在测量1微米以下的薄层时,都不能得到良好的精度。在硅的外延层和扩散层厚度的测量方面,还有一种球形滚槽测量法。这种方法很简便,而且在测量几千埃的薄层时精度很高。另外,除了外延层,还能直接测量各种绝缘膜、金属膜以及由这些膜     

用氮化硅作掩蔽的选择性硅外延生长

过去广泛地研究过用二氧化硅作掩蔽的硅选择性外延生长,但二氧化硅在氢气中易性能劣化,在硅选择性外延时二氧化硅要挥发,用氮化硅作掩蔽的选择外延可以避免这些问题。选择性外延是在硅衬底的所选择的区域作硅外延,其他区域则不外延,这种工艺在集成电路,尤其是互补电路中甚为重要。用四氯化硅的氢还原方法,在卧式反应器中通过氮化硅的窗口外延淀积硅。卧式反     

硅缓冲层提高选区外延生长硅基锗薄膜质量

研究了Si缓冲层对选区外延Si基Ge薄膜的晶体质量的影响。利用超高真空化学气相沉积系统,结合低温Ge缓冲层和选区外延技术,通过插入Si缓冲层,在Si/SiO_2图形衬底上选择性外延生长Ge薄膜。采用X射线衍射(XRD)、扫描电子显微镜(SEM)、原子力显微镜(AFM)表征了Ge薄膜的晶体质量和表面形貌。测试结果表明,选区外延Ge薄膜的晶体质量比无图形衬底外延得到薄膜的晶体质量要高;选区外延Ge薄膜前插入Si缓冲层得到Ge薄膜具有较低的XRD曲线半高宽以及表面粗糙度,位错密度低至5.9×10~5/cm^2,且薄膜经过高低温循环退火后,XRD曲线半高宽和位错密度进一步降低。通过插入Si缓冲层可提高选区外延Si基Ge薄膜的晶体质量,该技术有望应用于Si基光电集成。     

液相外延生长HgCdTe外延层

本文用滑舟式液相外延方法对HgCdTe薄膜的生长进行了研究。1.汞压控制。我们采用附加汞源的方法有效地控制了母液的成分。采用了三段温度分布的炉子。中间是反应区,温度为500℃。两边是控制汞压区。氢气流上方的汞槽在一定温度下产生汞蒸气压和反应区内母液的蒸气压相平衡。出口处的高温区形成热阻,以阻     

Passivation of a (100) Silicon Surface by Silicon Dioxide Grown in Nitric Acid

This letter investigates silicon dioxide layers grown at low temperature in concentrated nitric acid using a two-step process developed by Imai for thin-film transistors. With photoconductance measurements, we find that, prior to an anneal, nitric acid oxidation does not passivate the silicon surface, but, after a 30-min nitrogen anneal at 1100 $^{circ}hbox{C}$, a surface recombination velocity (SRV) of 107 cm/s (at $Delta n = hbox{10}^{15} hbox{cm}^{-3}$ ) is attained on 1-$Omegacdothbox{cm}$ n-type silicon. The SRV is further decreased to 42 cm/s after a 30-min forming gas anneal (FGA) at 400 $^{circ}hbox{C}$, which is equivalent to a thermal oxide under similar annealing conditions, although it is not stable and returns to its pre-FGA state over time. Capacitance–voltage and photoconductance measurements suggest that the oxides contain a high positive fixed charge—particularly after a 1100 $^{circ}hbox{C} hbox{N}_{2}$ anneal—which aids the passivation of n-type and intrinsic silicon but harms the passivation of low-resistivity p-type silicon.      

Amorphous Silicon Carbon Nitride Films Grown by the Pulsed Laser Deposition of a SiC‐Si3N4 Mixed Target

We grew amorphous SiCN films by pulsed laser deposition using mixed targets. The targets were fabricated by compacting a mixture of SiC and Si₃N₄ powders. We controlled the film stoichiometry by varying the mixing ratio of the target and the target‐to‐substrate distance. The mixing ratio of the target had a dominant effect on the film composition. We consider the structures of the SiCN films deposited using 30 ~ 70 wt.% SiC in the target to be an intermediate phase of SiC and SiNx. This provides the possibility of growing homogeneous SiCN films with a mixed target at a moderate target‐to‐substrate distance.     

Optical Characterization of GaN Grown by Plasma Source MBE

By using spectroscopic photoconductance, transmittance and luminescence methods, the optical characterization of GaN grown by plasma source MBE have been evaluated.The imperfection of the epitaxial layer deduced from the measured results have been discussed.The transient responses of the photoconductive detectors have been measured .Two time constants of 0.17ms and 6.85 ms at room temperature are deduced from the measured results.The origins have also been discussed.     

Planar Silicene: A New Silicon Allotrope Epitaxially Grown by Segregation

2D sheets of graphene‐like silicon, namely planar silicene, are synthesized. This new silicon allotrope is prepared on Au(111) thin films grown on a Si(111) substrate in the process of surface segregation. Owing to its almost perfectly flat geometry it shares the atomic structure with graphene rather than with low‐buckled silicene. Scanning tunneling microscopy measurements clearly display an atomically resolved planar silicene honeycomb lattice. Ab initio density functional theory calculations fully support the experimental findings and predict a pure sp² atomic configuration of Si atoms. The present work is the first experimental evidence of epitaxial planar silicene.     

具有纵向源极场板的绝缘体上硅器件新结构

采用软件仿真一系列横向双扩散金属氧化物半导体场效应管(Laterally double-diffused metal oxide semiconductor,LDMOS)结构,为缓解绝缘体上硅(Silicon on insulator,SOI)器件的击穿电压VB和漂移区的比导通电阻Ron.sp之间的矛盾关系,提出了一种具有纵向源极场板的双槽SOI新结构。该结构首先采用槽栅结构,以降低比导通电阻Ron.sp;其次,在漂移区内引入SiO_2介质槽,以提高击穿电压VB;最后,在SiO_2介质槽中引入纵向源极场板,进行了电场重塑。通过仿真实验,获得器件表面电场、纵向电场曲线及器件击穿时的电势线和导通时的电流线等。结果表明,新结构的VB较传统LDMOS器件提高了121%,Ron.sp降低了9%,器件优值FOM值达到15.2 MW·cm~(-2)。     

RLH/VLP-CVD低温赝同质外延硅膜微结构(英文)

The low-temperature processes for fabricating integrated circuits has become essential to the continuous development of smaller, faster solid-state devices and circuits. We have developed a new method, Rapid Lamp Heating/Very Low Pressure-Chemical Vapor Deposition for low-temperature silicon epitaxy. In this paper we study the microstructure of low-temperature(650-800℃) pseudo-homoepitaxial thin silicon films grown by RLH/VLP-CVD using HREM, TEM, SEM, X-ray diffraction technique and Raman spectroscopy. The results indicate that the epilayer is a high quality single crystal layer with a smooth and continuous interface.     

重碳掺杂p型GaAsSb的GSMBE生长及其特性

以四溴化碳(CBr4)作为碳掺杂源,采用气态源分子束外延(GSMBE)技术生长了InP衬底上晶格匹配的重碳掺杂p型GaAsSb材料.通过改变CBr4压力,研究了掺杂浓度在(1～20)×1019cm-3范围内的掺杂特性,得到的最大掺杂浓度为2.025×1020cm-3,相应的空穴迁移率为20.4cm2/(V·s).研究了不同生长温度对掺碳GaAsSb外延层组分、晶格质量和表面粗糙度的影响,结果表明480℃是生长优良晶格质量的最优温度.     

重碳掺杂p型GaAsSb的GSMBE生长及其特性

以四溴化碳(CBr4)作为碳掺杂源,采用气态源分子束外延(GSMBE)技术生长了InP衬底上晶格匹配的重碳掺杂p型GaAsSb材料.通过改变CBr4压力,研究了掺杂浓度在(1～20)×1019cm-3范围内的掺杂特性,得到的最大掺杂浓度为2.025×1020cm-3,相应的空穴迁移率为20.4cm2/(V·s).研究了不同生长温度对掺碳GaAsSb外延层组分、晶格质量和表面粗糙度的影响,结果表明480℃是生长优良晶格质量的最优温度.     

退火对MOCVD法生长ZnO薄膜性能的影响

采用MOCVD方法在(001)Si衬底上生长ZnO薄膜,并在空气中800℃退火1 h.生长及退火样品的XRD图谱均显示了较强的(002)ZnO衍射峰,表明ZnO薄膜为c轴高取向生长.光电子能谱(XPS)分析显示,退火后ZnO薄膜从富Zn生长变为富O生长.在样品的室温PL 谱中,观察到未退火样品的紫外发射峰的中心为3.28 eV,并观察到退火样品位于3.30 eV的自由激子发射峰和位于3.23 eV的施主-受主对的复合发光峰.实验结果表明,退火后ZnO薄膜的晶体质量得到提高.