扩散阻挡层用WTi合金的制备及其表征

Preparation and characterization of WTi alloy for diffusion barrier layer

WTi合金具有低的电阻系数、良好的热稳定性能和抗氧化性能,已被成功地应用于半导体器件的扩散阻挡层。迄今为止,中国大量半导体行业用靶材仍从国外进口。因此,通过研究靶材制备工艺及性能的关系,制备出高密度、高纯度、富钛相β1(Ti,W)少的WTi合金靶材,不仅能够把握相关领域发展方向,并且具有十分可观的市场前景。本文用行星球磨的方式对Ti、W粉末进行预处理及混合,得到不同粒度组成的混合粉末,用真空热压法对粉末进行成型,制备得到的WTi10合金。利用X射线衍射仪(XRD)、金相和扫描电子显微镜(SEM)分析混合粉末的粒度组成,并对合金的结构和形貌进行分析,采用排水法及ICP测试仪,分析合金的密度及杂质含量。结果表明,在温度1 200℃,压力30 MPa的真空热压条件下,制备得到的4个样品均已形成体心立方β相的WTi固溶体。且混粉球磨时间对WTi固溶体的峰位及峰强没有影响。但粉末混合球磨时间对热压后合金的微观组织形貌影响较大,随着混粉时间的延长,富钛相β1呈先减少后增加的趋势,混粉3 h的热压得到的样品黑色富Ti固溶体相区域最少,性能最优,合金的密度均达到理论密度的99.48%,纯度>99.97%。采用该方法制备得到的WTi10合金可用于磁控溅射制备WTi扩散阻挡层。以上研究为真空热压法制备半导体行业用钨钛靶材的研究提供一定的基础研究数据。

Because of low resistance coefficient,good thermal stability and oxidation resistance,WTi alloy has been successfully applied to the diffusion barrier layer of semiconductor device.So far,The target used in China semiconductor industry is mostly imported from abroad. Therefore,by studying the relationship between preparation process and the performance of target,to get high density,high purity titanium,and less β1(Ti,W) phase WTi alloy.W and Ti mixed powders with different particle sizes were obtained by the planetary ball milling. The WTi10 alloy was prepared by vacuum hot pressing. X ray diffraction(XRD),scanning electron microscope(SEM) were used to analyze morphology of the alloy and the particle size of the composite powder and the structure. The density and impurity cotent were analyzed by the method of drainage method and ICP test. The results showed that in the temperature 1 200 ℃,30 MPa pressure vacuum hot pressing conditions,the WTi alloy have been formed body centered cubic beta phase WTi solid solution. The powder mixed time have no effect on the peak position and peak strength of WTi solid solution. But powder mixed time affect alloy microstructure morphology greatly,longer duration of mixed powder,rich titanium phase β1 showed a trend of increase after the first reduce,mixed powder samples of 3 hours get rich Ti solid solution phase area at least,optimal performance,the density of alloy achieves 99.48% of theoretical density,the purity is more than 99.97%. WTi alloy prepared by this method can be used for the preparation of the diffusion barrier layer by magnetron sputtering. The above research provided basic data for the research of vacuum hot-pressed magnetic WTi target.