工作参数对平面磁控溅射系统沉积速率的影响

为了分析磁场、阴极电压、气压和靶基板间距等工作参数对沉积速率的影响,本文对磁控放电过程和沉积过程进行了讨论,并着重对沉积速率计算的无碰撞模型和碰撞模型进行了研究。靶功率是影响沉积速率的关键因素,通过对磁控放电特性分析发现,随着磁场、电压的增大,等离子体阻抗降低,放电电流和靶功率增大,随着气压的增大,放电电流和靶功率先增大后减小;采用碰撞模型对沉积速率进行模拟发现,在靶功率恒定的情况下,沉积速率随着气压和靶基板间距的增大而减小。因此,在气压和靶基板间距保持恒定的情况下,沉积速率会随着磁场和电压的增大而增大;而在磁场、电压和靶基板间距保持恒定的情况下,沉积速率随着气压的增大,先增大后减小。上述结论对于薄膜制备效率和质量的提高具有一定的理论指导意义。

工作参数对平面直流磁控溅射放电特性的影响

基于OOPIC软件,对平面直流磁控溅射放电等离子体进行了二维自洽粒子模拟,重点研究了磁场、阴极电势和气压等工作参数对磁控放电特性的影响。模拟发现,在一定的工作参数范围内,随着磁场的增强,鞘层厚度变窄,鞘层电势降减小,阴极离子密度增大,但是分布变窄;随着阴极电势的增加,鞘层厚度稍微变窄,鞘层电势降增大,阴极离子密度增大,分布变宽;随着气压的升高,鞘层厚度基本不变,鞘层电势降会增大,阴极离子密度先增大后减小,分布略微变宽。

Simulation to Predict Target Erosion of Planar DC Magnetron

Plasma properties in a planar DC magnetron system are simulated by a non-self- consistent particle method in two dimensions. Through tracing the trajectories of the energetic electrons in the specified electric field and the magnetic field, and treating the collision process by Monte Carlo method, the spatial profile of ionization events can be obtained conveniently. Assuming that the ions speed up from the ionization points and bombard the target with the energy at these points, and according to the Yamamura/Tawara method, the target erosion can be predicted. The magnetic field is calculated by the finite element method, and the electric field is estimated according to the self-consistent simulation and measured results. The influence of the time step size on the target erosion profile is analysed first to find a proper step size. Then the influence of electric field estimated on the erosion profile is discussed. The erosion profile may become narrower if the sheath thickness is increased. Finally, considering the dynamic erosion process, the erosion profile may get wider over time for the magnetron with shunt bar.