Metallization over tungsten plugs
    1.
    发明授权
    Metallization over tungsten plugs 失效
    钨插头金属化

    公开(公告)号:US5407861A

    公开(公告)日:1995-04-18

    申请号:US68139

    申请日:1993-05-26

    摘要: A plug contact process wherein, after contact holes are etched, an adhesion layer (such as Ti/TiN) and a filler metal (such as tungsten) are deposited overall. A two-stage etch is then used: First, the filler metal is etched preferentially with respect to the adhesion layer, until an endpoint signal first indicates that said adhesion layer is exposed. No overetch is used at this stage. Thereafter a nonpreferential etch is used to clear residues of the filler metal, while also uniformly reducing the height of the adhesion layer. This prevents the tops of the plugs in the contact holes from being recessed. Aluminum (or other metal) is then deposited and patterned (using a stack etch to remove the undesired portions of the adhesion layer too) to implement the desired wiring pattern. This process thereby reduces voids, and resulting metallization defects, in a process with high-aspect-ratio contacts. In addition, the residual adhesion layer helps to reduce electromigration.

    摘要翻译: 一种插头接触方法,其中在接触孔被蚀刻之后,整体上沉积粘合层(例如Ti / TiN)和填充金属(例如钨)。 然后使用两级蚀刻:首先,相对于粘合层优先蚀刻填充金属,直到端点信号首先指示所述粘合层暴露。 在这个阶段没有使用过筛。 此后,使用非优选蚀刻来清除填充金属的残留物,同时也均匀地降低粘附层的高度。 这防止了接触孔中的插塞的顶部凹陷。 然后将铝(或其他金属)沉积并图案化(使用叠层蚀刻以除去粘附层的不希望的部分),以实现所需的布线图案。 因此,在具有高纵横比接触的过程中,该过程减少了空隙以及所得到的金属化缺陷。 另外,残留粘附层有助于减少电迁移。