两步镍硅化工艺及保护氮气的作用

A two-step process of Ni silicide formed on bulk silicon, and the effects of different process conditions, including two-step RTA temperature and time, selective etching, and process protective nitrogen gas on the properties of the Ni silicide film have been studied. In particular, the experiments show that the quality of NiSi film is very sensitive to the process conditions of the first RTA. The experiments also show that the quality of the film is very sensitive to the flow of protective nitrogen gas. The corresponding mechanisms are discussed.     

Ti中间层对超薄Ni膜硅化反应特性的影响

在多种Si衬底上利用离子束溅射淀积超薄Ni膜以及Ni/Ti双层膜,经过快速热退火处理完成薄膜的固相硅化反应,通过四探针法、微区喇曼散射法和俄歇深度分布测试法研究了Ti中间层对Ni硅化反应的影响. 实验结果证明Ti中间层抑制了集成电路生产最需要的NiSi相的形成.     

掺Pt对Si(100)上形成的NiSi薄膜应力的影响

利用在线应力测试技术表征了掺入Pt后对镍硅化物薄膜应力性质的影响.通过改变NiSi薄膜中Pt含量以及控制热处理的升温、降温速率实时测量了薄膜应力,发现在Si(100)衬底上生长的纯NiSi薄膜和纯PtSi薄膜的室温应力主要是热应力,且分别为775MPa和1.31GPa,而对于Ni1-xPtxSi合金硅化物薄膜,室温应力则随着Pt含量的增加而逐渐增大.应力随温度变化曲线的分析表明,Ni1-xPtxSi合金硅化物薄膜的应力驰豫温度随Pt含量的增加,从440℃(纯NiSi薄膜)升高到620℃(纯PtSi薄膜).应力驰豫温度的变化影响了最终室温时的应力值.     

掺Pt对Si(100)上形成的NiSi薄膜应力的影响

利用在线应力测试技术表征了掺入Pt后对镍硅化物薄膜应力性质的影响.通过改变NiSi薄膜中Pt含量以及控制热处理的升温、降温速率实时测量了薄膜应力,发现在Si(100)衬底上生长的纯NiSi薄膜和纯PtSi薄膜的室温应力主要是热应力,且分别为775MPa和1.31GPa,而对于Ni1-xPtxSi合金硅化物薄膜,室温应力则随着Pt含量的增加而逐渐增大.应力随温度变化曲线的分析表明,Ni1-xPtxSi合金硅化物薄膜的应力驰豫温度随Pt含量的增加,从440℃(纯NiSi薄膜)升高到620℃(纯PtSi薄膜).应力驰豫温度的变化影响了最终室温时的应力值.     

镍硅化物工艺新进展

随着MOSFET器件的特征尺寸进入亚100 nm,传统自对准硅化物材料,如TiSi_2和CoSi_2,由于其硅化物形成工艺的高硅耗、高形成热预算和线宽效应等特点,已不能满足纳米尺寸器件对硅化物材料的要求,显现出其作为自对准硅化物材料的局限性.NiSi与传统自对准硅化物材料相比,不但具有硅化物形成工艺的低硅耗和低形成热预算,而且具有低电阻率,又不存在线宽效应.所以,NiSi作为纳米尺寸器件最有希望的自对准硅化物材料得到广泛的关注和研究.综合介绍了镍硅化物特性,一硅化镍薄膜形成工艺及其工艺控制问题.     

In situ X-ray diffraction study of thin film Ir/Si solid state reactions

The solid state reaction between a thin (30 nm) Ir film and different Si substrates (p-type Si(1 0 0), n- and p-type Si(1 1 1), silicon on insulator (SOI) and polycrystalline Si) was studied using a combination of in situ X-ray diffraction (XRD), in situ sheet resistance and laser light scattering measurements. No significant influence of either the dopants or the substrate orientation was detected as a phase formation sequence of IrSi, Ir₃Si₄,Ir₃Si₅ and IrSi₃ was found for all samples. The presence of a thin (<4 nm) amorphous IrSi film at room temperature and its subsequent crystallization could be deduced from the appearance of a broad semi-amorphous diffraction peak in the XRD spectrum around 400 °C. The results were verified using ex situ Rutherford Backscattering Spectroscopy, Scanning Electron Microscopy and 4-point probe measurements on quenched samples. The activation energy of the crystallization process and the silicide growth was determined using a Kissinger analysis on ramp anneals with different ramp rates. In addition, the influence of up to 25 volumetric % (20.5 atomic %) of Ir to the silicide formation in the Ni/Si system was studied on SOI and polycrystalline Si substrates. In the presence of Ir, the temperature range over which the low resistivity NiSi exists, is reduced both through an increase in formation temperature and an earlier consumption by the formation of NiSi₂. After the heat treatment, a continuous distribution of Ir throughout the NiSi₂ phase was detected using X-ray photoelectron spectroscopy depth profiling. A low sheet resistance of was maintained on both substrates up to 900 °C.     

非晶化注入技术在NiSi SALICIDE工艺中的应用

在pn结形成之后借助非晶化Si离子注入技术可以将结表面Si单晶层非晶化. 作者研究了这种非晶化处理对Ni硅化反应的影响. 实验发现,非晶化处理可以促进Ni在低温下与衬底Si的反应,而且在低温下Ni/Si可以直接反应形成NiSi. 实验结果表明这种非晶化未对硅化反应过程中杂质的再分布产生影响,但是剖面透射电镜分析表明,这种非晶化所需能量需要合理优化.     

Schottky barrier height of a new ohmic contact NiSi2 to n-type 6H-SiC

We present a new ohmic contact material NiSi₂ to n-type 6H-SiC with a low specific contact resistance. NiSi₂ films are prepared by annealing the Ni and Si films separately deposited on (0 0 0 1)-oriented 6H-SiC substrates with carrier concentrations (n) ranging from 5.8×10¹⁶ to 2.5×10¹⁹ cm⁻³. The deposited films are annealed at 900 °C for 10 min in a flow of Ar gas containing 5 vol.% H₂ gas. The specific contact resistance of NiSi₂ contact exponentially decreases with increasing carrier concentrations of substrates. NiSi₂ contacts formed on the substrates with n=2.5×10¹⁹ cm⁻³ show a relatively low specific contact resistance with 3.6×10⁻⁶ Ω cm². Schottky barrier height of NiSi₂ to n-type 6H-SiC is estimated to be 0.40±0.02 eV using a theoretical relationship for the carrier concentration dependence of the specific contact resistance.     

Ni/Pd/Si固相反应及NiSi热稳定性增强研究

研究了Ni/Pd双层薄膜在硅衬底上的硅化物形成过程.结果表明,加入Pd层后,退火形成Ni1-xPdxSi固熔体,该固熔体比NiSi的热稳定性好,使得NiSi向NiSi2的转变温度升高.加入Pd的量越多,NiSi2的成核温度越高,并用经典成核理论解释了该现象.     

Post-Silicide杂质分凝工艺调节NiSi/n-Si肖特基势垒高度

The post-silicide of dopant segregation process for adjusting NiSi/n-Si SBH（Schottky barrier height）is described.Adopting the analysis of the I–V characteristic curve and extrapolating the SBH of NiSi/n-Si Schottky junction diodes（NiSi/n-Si SJDs）,the effects of different of process parameters dopant segregation,including segregation anneal temperature and dopant implant dose,on the properties of the NiSi/n-Si SJDs have been studied,and the corresponding mechanisms are discussed.     

Thickness scaling issues of Ni silicide

Ni silicidation processes without a capping layer and with a TiN capping layer are studied from the point of view of process window, morphology of the resulting silicide, and mechanisms of degradation at higher temperatures. The thermal stability of NiSi films on As- and on B-doped (100) Si substrates was investigated for Ni film thicknesses ranging from 5 to 30 nm. While agglomeration was the mechanism of degradation for the thin films, both morphological changes and transformation to NiSi₂ were possible for thicker films depending on anneal temperature and time. Activation energy of 2.5 eV for NiSi on n+ (100) Si and p+ (100) Si was determined for the process of morphological degradation. The measured temperature and time dependences for the thermal degradation of NiSi films suggest that the activation energy for transformation to NiSi₂ is higher than for morphological degradation.     

取代化学镍金用于线宽线距小于30μm高密度印制板的新技术

化学镀镍/金具有优良的性能,已在印制电路板上获得广泛应用.但随着线路的线宽线距越来越小钯催化剂会夹杂在线路之间造成化学镀镍经常出现超镀现象,使化学镀镍/金工艺无法应用.为了解决此问题,我们发现用0.2 μm厚的微碱性化学镀银层具有化学镀镍/金层相同的可焊性和打线功能,证明微碱性化学镀银工艺可以取代超高密度PCB的化学镀...     

纳米化学复合镀的开发及在PCB制造中的应用研究

化学镀表面处理技术使用范围很广,镀层均匀、装饰性好;在防护性能方面,能提高产品的耐蚀性和使用寿命;在功能性方面,能提高加工件的耐磨性和导电性、润滑性能等特殊功能,因而成为表面处理技术的一个重要部分。钠米化学复合镀是在化学镀液中加入纳米粒子,使其与化学镀层共沉积的工艺技术。文章主要研究在化学镀Ni-P中加入纳米颗粒,在基体表面沉积具有镀厚均匀、耐磨、耐腐蚀、可焊的纳米复合镀层,阐明镀液组成和工艺条件对沉积速率、镀液稳定性、镀层与基体的结合力的影响,获得钠米化学复合镀技术的工艺参数,并对纳米复合镀层的性能进行了研究。