基于倾斜旋转方法磁控溅射制备TSV阻挡层

Preparation of TSV Barrier Layer by Magnetron Sputtering Based on Inclined Rotation Method

硅通孔(TSV)是实现三维集成的关键技术,在TSV侧壁制备连续和均匀的阻挡层至关重要。提出了一种磁控溅射制备TSV侧壁阻挡层的方法,将溅射基台倾斜一定角度并水平匀速旋转,使溅射离子的掉落方向与TSV侧壁不平行,靶材离子更容易溅射沉积在TSV侧壁,使得TSV侧壁都能被溅射到,更有利于制备连续和均匀的阻挡层。使用Ti靶进行直流磁控溅射,优化溅射电流和溅射气压,通过扫描电子显微镜(SEM)对TSV侧壁阻挡层的形貌进行表征分析。随着溅射电流和溅射气压的增大,阻挡层的厚度会增加,但是溅射气压的增大使得溅射钛晶粒变得细长,从而导致阻挡层的均匀性和致密性变差。

The through silicon via(TSV)is a crucial technology for achieving three-dimensional integration,and it is essential to prepare a continuous and uniform barrier layer on the sidewall of TSV.A magnetron sputtering method for preparing a sidewall barrier layer on TSV was proposed,where the sputtering base was tilted at a certain angle and rotated horizontally at a constant speed,so that the deposition direction of sputtered ions was not parallel to the TSV sidewalls,and the target ions were more likely to be sputtered and deposited onto the TSV sidewalls.As a result,all the TSV sidewalls can be sputtered,which is more favorable for the preparation of a continuous and uniform barrier layer.Direct current magnetron sputtering using a Ti target was employed to optimize the sputtering current and pressure,and the morphology of the TSV sidewall barrier was characterized and analyzed by scanning electron microscope(SEM).It is found that the thickness of the barrier layer increases with the increase of the sputtering current and pressure.However,higher sputtering pressure leads to elongated titanium grains,which reduces the uniformity and compactness of the barrier layer.