Polyimide inter-metal dielectric process
    2.
    发明授权
    Polyimide inter-metal dielectric process 失效
    聚酰亚胺金属介电工艺

    公开(公告)号:US4495220A

    公开(公告)日:1985-01-22

    申请号:US540064

    申请日:1983-10-07

    摘要: A technique for employing polyimide as an inter-metal dielectric layer, while avoiding the difficulties usually associated with this material. An upper layer of silicon dioxide is employed as a hard mask over the polyimide, and is highly doped with phosphorous to prevent thermal cracking. Via holes are formed in a multi-stage etching process that includes a first dry-etching step that effects isotropic etching to form holes with desirably sloped sidewalls, and a second dry-etching step that effects anisotropic etching to extend the via holes through to a lower metal surface without significantly enlarging the holes in width. Finally, a dry-etching step is used to remove any residue of polyimide and to strip the silicon dioxide layer from over the polyimide. The bottom of the hole is then sputter-etched prior to metallization. In one preferred form of the method, a lower layer of silicon dioxide is formed between the lower metal layer and the polyimide layer, to facilitate removal of polyimide residue and to act as a barrier between the lower metal and the polyimide.

    摘要翻译: 使用聚酰亚胺作为金属间介电层的技术,同时避免了通常与该材料相关的困难。 在聚酰亚胺上使用二氧化硅上层作为硬掩模,并且高度掺杂有磷以防止热裂解。 在多级蚀刻工艺中形成通孔,其包括实现各向同性蚀刻以形成具有期望的倾斜侧壁的孔的第一干蚀刻步骤,以及第二干蚀刻步骤,其实现各向异性蚀刻以将通孔延伸到 下部金属表面,而不会明显扩大孔的宽度。 最后,使用干蚀刻步骤去除聚酰亚胺的任何残余物并从聚酰亚胺上剥离二氧化硅层。 然后在金属化之前对孔的底部进行溅射蚀刻。 在该方法的一个优选形式中,在下金属层和聚酰亚胺层之间形成下层二氧化硅,以便于去除聚酰亚胺残留物并用作下金属和聚酰亚胺之间的阻挡层。