W-via failure and process optimization of interconnect metallization for 0.14 um 256MDRAM

摘要

Tungsten chemical vapor deposition (W-CVD) has been widely used for mutlilevel metallization. Because W-CVD process has the advantage of excellent gap-fill ability , it is widely used for high aspect ratio contact or via process. For deep sub-micro process, the aspect ratio increases and gap-fill ability becomes more challenge than before. It was found the via failure phenomenon in backend interconnect metallization of 0.14um process According the related experiment , it shows the root cause is from the via-fill ability issue . By the split condition, it shows the via-fill failure can be fixed by process optimization.