摘要:本文利用第一性原理计算方法对Cu在Ta表面上的粘附性进行初步模拟,所有计算采用广义梯度近似下的平面波赝势方法。具体来说是基于总能量的概念来对晶格结构进行几何优化,应用吸附能和形成能公式计算能量差值。通过比较结果发现,第二层Ta原子对应的堆栈位是最稳定的相,并在最优位置讨论Cu原子覆盖率、杂质对粘附性的影响。结果发现在Cu覆盖率为1时,杂质对粘附性的影响很大。这为实验研究提供可能的实现途径和物理背景。
关键词:铜互连;钽粘附层;吸附;第一性原理
Abstract:In this paper copper adhesion on tantalum surface has been studied with first-principles calculation method, all calculations employing plane wave pseudopotential method with the generalized gradient approximation. Specifically, lattice structure is used for geometry optimization on the basis of the concept of the total energy, and the energy difference is calculated by the adhesion energy and the formation energy formula. By comparative analysis results reaches the conclusion that the second layer Ta atoms corresponding stack position is the most stable site. Then the effect of coverage on the adhesion energy is studied. Finally the influence of impurities on adhesion has also been studied as the copper coverage is one. This may provide possible ways and physical background for experimental study.
Key words:Cu interconnection; Tantalum adhesion layer; Adhesion; First-principles