| 摘要 |
PROBLEM TO BE SOLVED: To prevent a decline of wiring reliability arising from a stress, in an area between upper and lower plugs in a multi-layer wiring structure of a semiconductor device having a stack structure. SOLUTION: In a multi-layer wiring structure causing a resistance variation due to long time storage at high temperature, a void 40 is observed in wiring 4 between an upper plug 3 and a lower plug 6. Parts 43, 44 between upper and lower plugs 3, 6 have crystal grains of smaller size than that of other parts, and have different plane orientation from that of other parts. For this reason, in order to raise wiring reliability, a wiring stress is lessened by shifting a center of contact surfaces between upper and lower plugs, or sputtering temperature is set so as not to give rise to crystal grain boundaries between upper and lower plugs, when a wiring layer of aluminum or an aluminum alloy is formed. |
