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1.
A two-step rapid thermal diffusion process of boron into silicon using a boron nitride solid diffusion source is described.
During the first step, HBO2 glass is transferred onto the silicon wafer from the diffusion source by keeping the temperature of the silicon wafer at
750° C while the diffusion source is at about 900° C. Boron is, then, diffused into the silicon wafer from HBO2 glass at 1000° C or 1100° C in N2 during the second step. Extremely shallow junctions with junction depths of about 20 nanometers and sheet resistances of
about 350 ohms/sq can be achieved with this method as well as relatively deep junctions with junction depths of about 175
nanometers and sheet re-sistances of about 55 ohms/sq. When the diffusion is performed at 1100° C, both the junction depth
and electrically active boron concentration at the surface increase as the ambient gas is changed from N2 to O2 while the sheet resistance decreases. A boron rich layer which has high resistivity is not formed at the surface when the
diffusion is performed at 1100° C in O2 ambient.
This work was supported by Ministry of Science and Technology, Korea 相似文献
2.
In this paper, we present an atomistic kinetic Monte Carlo (KMC) model for boron diffusion in amorphous silicon (a-Si). Boron diffusion is assumed to be indirect, mediated by dangling bonds (DBs) present in a-Si. The model shows a transient character due to a-Si relaxation modeled by DB annihilation. In addition, B produces clusters at higher concentrations, leading to an immobile B part. The model, when calibrated, has been successfully applied to experiments of thermal anneals of amorphized B marker layers and B implantation into preamorphized Si. In addition, we studied the contribution of B diffusion in a-Si in ultrashallow junction (USJ) formation of advanced technologies. We have also used the model to demonstrate how the contribution to diffusion of B in a-Si in current and future technologies can be higher than in c-Si. 相似文献
3.
4.
采用闭管扩散方式,对不同结构的异质结外延材料In0.81Al0.19As/In0.81Ga0.19As、InAs0.6P0.4/In0.8Ga0.2As、InP/In0.53Ga0.47As实现了Zn元素的P型掺杂,采用扫描电容显微技术(SCM)和二次离子质谱(SIMS)研究了在芯片制备中高温快速热退火(RTP)处理环节对p-n结结深的影响。结果表明:由于在这3种异质结外延材料中掺杂的Zn元素并未完全激活,导致扩散深度明显大于p-n结结深;高温快速热退火处理并不会显著影响结深的变化,扩散完成后的p-n结深度可以近似为器件最终的p-n结结深;计算了530℃下Zn在In0.81Al0.19As、InAs0.6P0.4、InP中的扩散系数D分别为1.327×10-12cm2/s、1.341 10-12cm2/s、1.067×10-12cm2/s。 相似文献
5.
S. Batra K. H. Park S. K. Banerjee G. E. Lux C. L. Kirschbaum J. C. Norberg T. C. Smith J. K. Elliott B. J. Mulvaney 《Journal of Electronic Materials》1992,21(2):227-231
Grain microstructure has a major impact on diffusion of P in polysilicon-on-single crystal silicon systems both within the
polysilicon layer and inside the single crystal silicon substrate. During annealing, P diffuses very rapidly along grain boundaries
in the polysilicon layer to the interface, where it undergoes very fast diffusion laterally along the polysilicon-single crystal
silicon interface, followed subsequently by slow indiffusion into the underlying substrate. However, the extrapolated Secondary
Ion Mass Spectrometry profiles for P reveal a discontinuity at the interface, which is caused by anomalous diffusion behavior
similar to the well known “kink” effect observed in single crystal silicon during P diffusion. The high diffusivity tail region
is also much less pronounced for polysilicon-on-silicon systems compared to single crystal silicon due to a reduction of interstitial
supersaturation in the substrate. This reduction is believed to result from the absorption of interstitials by the grain boundaries
which act as sinks for the excess interstitials. 相似文献
6.
7.
Daniel F. Downey Steven D. Marcus Judy W. Chow 《Journal of Electronic Materials》1998,27(12):1296-1314
The effects of time, temperature, ramp-up, and ramp-down rates with rapid thermal annealing employing a STEAG AST SHS3000 were investigated on 1.0 and 2.0 keV 11B+, 2.2, 5.0, and 8.9 keV 49BF 2 + , and 2 KeV 75As+, 1E15/cm2 samples implanted in a Varian VIISion-80 PLUS ion implanter at 0o tilt angles. These annealed samples were analyzed by four-point probe, secondary ion mass spectrometry (SIMS), and in select cases by spreading resistance profiling (SRP) and transmission electron microscopy (TEM). To ensure reproducibility and to minimize oxidation enhanced diffusion as an uncontrolled variable, the O2 background concentration in N2 was maintained at a controlled low level. Under these conditions, ramp-rates alone were found not to be significant. Spike anneals (1050°C, ~ 0 s) with fast ramp-rates (240°C/s) and fast cool down rates (86°C/s) provided the shallowest junctions, while still yielding good sheet resistance values. Post annealed samples were examined for extended defect levels (by TEM) and trapped interstitial concentrations. Fluorine concentration measurements were employed to qualitatively explain differences in the B diffusion from 11B+ and 49BF 2 + ion implants at various energies. The 2.2 keV 49BF 2 + “fast” spike annealed sample at 1050°C exhibited limited, if any, enhanced diffusion, yielding a SIMS junction depth of 490Å, an electrical junction of 386Å (by SRP) and a sheet resistance of 406 ohm/sq. 相似文献
8.
多晶硅薄膜比非晶硅薄膜具有更高的电子迁移率,在器件中表现出更优良的性能,脉冲激光结晶非晶硅薄膜制备多晶硅薄膜的方法具有热积存小、对衬底影响小、成本低等优点。使用532 nm固体纳秒激光器进行了非晶硅薄膜激光结晶实验,为了解决直接使用高斯光束结晶时因光斑能量分布带来的结晶效果不均匀,首先基于光束整型系统将圆形的高斯光束整型成为线性平顶光束,而后研究单脉冲能量密度、脉冲个数、非晶硅薄膜厚度对结晶效果的影响。结果表明,线性平顶光束用于非晶硅薄膜结晶具有更好的均匀性,对于100 nm非晶硅薄膜,随着能量密度的增加,晶粒逐渐变大,直到表面出现热损伤,最大晶粒尺寸约为1 μm×500 nm。随着脉冲个数的增加,表面粗糙度有减小的趋势,观察到的最小粗糙度约为2.38 nm。对于20 nm超薄非晶硅薄膜,只有当能量密度位于134 mJ/cm2和167 mJ/cm2之间、脉冲个数大于或等于八个时才能观察到明显的结晶效果。 相似文献
9.
介绍了一种P型超浅结的制作工艺。该工艺通过F离子注入和快速热退火技术相结合,获得了比较先进的100nm以内的P型超浅结;重点研究了影响超浅结形成的沟道效应和瞬态增强扩散效应;详细介绍了制作过程中对沟道效应和瞬态增强扩散效应的抑制。 相似文献
10.
S. Chittipeddi C. M. Dziuba V. C. Kannan M. J. Kelly W. T. Cochran B. Rambabu 《Journal of Electronic Materials》1993,22(7):785-791
The effect of rapid thermally nitrided titanium films contacting silicided (titanium disilicided) and nonsilicided junctions
has been studied in the temperature range of 800 to 900°C. The rapid thermal nitridation of titanium films used as diffusion
barriers between aluminum and silicon, has a major impact on shallow junction complementary metal oxide semiconductor technologies.
During the process of rapid thermal nitridation, the dopants in the junctions undergo a redistribution and affect the electrical
properties of shallow junction structures. This work focuses on using novel contact resistance structures to measure the variation
in electrical parameters for rapid thermally nitrided titanium films annealed at different temperatures. The self-aligned
silicide (salicide) junctions in this study were formed using rapid thermally annealed titanium films. Electrical contact
resistance testers were used to measure the interface contact resistance between the salicide and silicon, as well as between
the metal and the salicide. The results show that the interface contact resistance to the p− diffused salicided junctions increases with rapid thermal nitridation of the additional titanium film, whereas the interface
contact resistance to the n− diffused salicided junction shows a decrease. Further, as a function of the rapid thermal annealing temperature (for fixed
titanium thickness), the nonsalicided diffusions show an increase in the interface contact resistance. The boron profiles
at the TiSi2/Si interface obtained using secondary ion mass spectroscopy show an excellent qualitative agreement with the electrical results
for each of the conditions discussed. The films were also characterized using Rutherford back-scattering spectrometry and
transmission electron microscopy and the results show good agreement with the measured variation in electrical parameters.
These results also show that as the anneal temperature is increased, the TiN thickness increases, further the change in the
silicide/silicon interface position with the nitridation of the additional titanium layer was verified.
This work was carried out when the author was working at AT&T Bell Labs 相似文献
11.
Low-thermal-budget annealing of ion-implanted BF
2
+
, P, and As in Si was studied for shallow-junction formation. Implant doses were sufficient to amorphize the silicon surface
region. Low-temperature furnace annealing and rapid-thermal annealing of ionimplanted boron, phosphorus and arsenic in silicon
exhibit a transient enhanced diffusion regime resulting injunction depths considerably deeper than expected. The origin of
this transient enhanced diffusion is the annealing of ion-implantation damage in the silicon substrate. We have found that
point-defect generation during the annealing of either shallow end-of-range damage or small clusters of point defects dominates
the transient enhanced diffusion process depending upon the annealing temperature and time. The net effect of damage annealing
is to reduce the activation energy for dopant diffusion by an amount equal to the activation energy of the supersaturation
of point defects in silicon. Models which can describe the transient enhancement characteristics in dopant diffusion during
both furnace and rapid-thermal annealing of these implants are discussed. 相似文献
12.
M. Pierro F. Bucci C. Cornaro 《Progress in Photovoltaics: Research and Applications》2015,23(11):1581-1596
Nowadays, there is a wide debate in literature related to the silicon thin films seasonal performance. Amorphous modules seem to react positively to the temperature, while the temperature parameters indicate a negative thermal response. Periodic fluctuations of nominal power due to light soaking and thermal annealing effects are observed. On the other hand, the module temperature reached in some open rack plants seems too low to activate annealing power regeneration process so that the seasonal performance trend may depend mainly on other effects such as spectral or irradiance. In the following paper, a model that allows to calculate the impact of all the phenomena that affect the photovoltaic performance is used. The light soaking and thermal annealing contributions are measured from outdoor data using two different methods. Both methods lead to similar results, and the model is able to reproduce the seasonal performance with an acceptable level of reliability on the day, hour, minute time scale. An analysis of each effect contribution to the seasonal performance is also provided. Thus, main open questions related to a‐Si thin films performance such as positive reaction to temperature and seasonal fluctuations are discussed. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
13.
报道了氢化非晶硅薄膜在600~620℃温度下快速退火10 s可以形成纳米晶硅,其拉曼散射表明,所形成的纳米晶硅在薄膜中的分布是随机的,其直径在1.6~15 nm内.根据晶体生长理论和计算机模拟,讨论了升温快慢与所形成纳米硅颗粒大小之间的关系,并且在强光照射下观察了纳米晶硅在薄膜中的结晶和生长情况.经退火形成的nc-Si可见光辐射较弱,不能检测到它们的光致发光,但用氢氟酸腐蚀钝化后则可检测到较强的红PL,并且钝化后的nc-Si在空气中暴露一定时间后,其辐射光波长产生了蓝移.就表面钝化和量子限制对可见光辐射的重要性作了讨论. 相似文献
14.
Steven Marcus Wilfried Lerch Daniel F. Downey Stanislov Todorov Judy Chow 《Journal of Electronic Materials》1998,27(12):1291-1295
Ion implants of 2.0 and 5.0 keV 11B+ and 2.2, 5.0, and 8.9 keV 49BF
2
+
at a dose of 1E15/cm2 were investigated. Anneal conditions were developed which produced highly activated yet shallow junctions. The effects of
oxygen were studied previously by us1–12 and found to be an important variable to control in order to produce uniform and repeatable sheet resistance and junction
depths. A purge procedure and integrated oxygen sensor were developed to measure and control the oxygen background concentration
for each anneal to assure repeatable results. “Shelf-life,” that is dwell time between implant and anneal, was investigated.
It was found that, for low energy implants, the amount of native oxide grown affects retained dose, sheet resistance (Rs),
and uniformity. Controlled oxygen level repeatability and shelf life results are presented and equipment designs are discussed. 相似文献
15.
C. Gontrand A. Merabet S. Krieger-Kaddour C. Dubois J. P. Vallard 《Journal of Electronic Materials》1993,22(1):135-141
The codiffusion of implanted boron and arsenic during rapid thermal annealing in a polysilicon/monocrystalline silicon system
used for high speed bipolar integrated circuit technology has been investigated. Such a process allows a uniformly high concentration
in the emitter regions. It induces a very shallow emitter-base junction depth for an n-p-n transistor. On the contrary, in
p-n-p configuration, when the arsenic dose is lower than the boron dose, boron deeply penetrates the single-crystal silicon,
causing problems for fabricating shallow junctions. The rapid thermal annealing-induced redistribution of arsenic and boron
implanted at various implant doses in a 380 nm low-pressure chemical vapor deposition (LPCVD) polysilicon layer has been studied
by secondary ion mass spectroscopy measurements. A strong lowering of the minority dopant diffusion in the polysilicon film
is observed due to the high concentration of the other dopant. This effect is mainly related to grain boundary trap saturation
while the electric field issued from dopant activation in the fastly recrystallized amorphous layer due to arsenic implantation
in the upper region of the LPCVD film has a lesser effect. Transmission electron microscopy measurements show that recrystallization
extends deeper than the amorphous layer, which is responsible for the increase of grain size. Sheet resistance measurements
have been performed as an approach to the electrical behavior for these structures. 相似文献
16.
17.
In this study we evaluate the effects of dual implantation with different doses of Si and P on dopant activation efficiency
and carrier mobility in InP:Fe. The implants were activated by a rapid thermal annealing step carried out in an optimized
phosphoruscontaining ambient. For high dose implants (1014–1015 cm−2), which are typically employed for source/drain regions in FETs, dual implantation of equal doses of Si and P results in
a higher sheet carrier concentration and lower sheet resistance. For 1014 cm−2 Si implants at 150 keV, the optimal P co-implant dose is equal to the Si dose for most anneal temperatures. We obtain an
activation efficiency of ∼70% for dual implanted samples annealed at 850° C for 10 sec. The high activation efficiencies and
low sheet resistances obtained in this study emphasize the importance of stoichiometry control through the use of P co-implants
and a phosphorus-containing ambient during the thermal processing of InP. 相似文献
18.
19.
Zhenghua An Miao Zhang Ricky K. Y. Fu Paul K. Chu Chenglu Lin 《Journal of Electronic Materials》2004,33(3):207-212
Relaxed SiGe-on-insulator (SGOI) is a suitable material to fabricate strained Si structures. Separation-by-implantation-of-oxygen
(SIMOX) is a competing method to synthesize SGOI materials. In this work, SiGe/Si samples were implanted with 3×1017 cm−2 oxygen ions at 60 kV, followed by high-temperature annealing. Oxygen segregation and Ge diffusion during the annealing process
were investigated using Rutherford backscattering spectroscopy/channeling (RBS/C), high-resolution x-ray diffraction (HRXRD),
and high-resolution transmission electron microscopy (HRTEM). Our results show that the sample structure strongly depends
on the thermal history and Ge diffuses mainly at the beginning stage of the high-temperature process. The process can be improved
by introducing an annealing step at a medium temperature before high-temperature annealing, and sharper interfaces and good
crystal quality can be obtained. Our results indicate that the SIMOX process for silicon-on-insulator (SOI) fabrication can
be adopted to produce SGOI. 相似文献
20.
R. Singh K. C. Cherukuri L. Vedula A. Rohatgi J. Mejia S. Narayanan 《Journal of Electronic Materials》1997,26(12):1422-1427
In this study, we used a vacuum ultraviolet (VUV) radiation source in conjunction with tungsten halogen lamps based rapid
thermal processing (RTP) system. The two light sources were arranged in different configurations to study the phosphorus diffusion
in silicon. The high energy VUV photons in conjunction with infrared and visible photons resulted in enhanced diffusion and
improved the bulk properties of silicon substrate. An improvement in the leakage currents of the diodes made from VUV irradiated
wafers is observed. A qualitative explanation of the results based on the role of high energy photons in RTP is presented.
High energy photons from VUV region to about 800 nm results in a decrease in the bond dissociation energies of the molecules,
since they are in electronic excited states. Higher activation of dopants and reduction in activation energies is observed.
The minority carrier lifetime measurements show that there is an enhanced phosphorus gettering and overall reduction of the
recombination-generation centers in silicon. 相似文献