Abstract
For several microelectronics applications, Cu/dielectric adhesion is a key reliability issue. Either electroplating or local galvanic coupling under moist operating conditions may result in hydrogen induced interface weakening. The present study compared hydrogen effects on Cu/SiO2 adhesion for sputter deposited films with and without Ti underlayers. Thin Cu and Cu/Ti films ranging from 80-3000 nm have been evaluated. Direct observations of the surface during electrolytic charging have shown no evidence of film/substrate debonding for Cu/Ti systems. In contrast, extensive delaminations have been observed for Cu films. Indentation testing immediately after charging indicated up to 100% decrease in the practical adhesion for Ti/Cu films. The observed effect resulted from a true interfacial fracture energy reduction from 4 to 2 J/m2. Plastic energy dissipation was assumed unaffected as no yield stress changes were detected after charging. Even with the deleterious effect of hydrogen, adhesion strength of Cu/Ti films remained higher than that of non-charged Cu films.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 269-273 |
| Number of pages | 5 |
| Journal | Materials Research Society Symposium - Proceedings |
| Volume | 563 |
| DOIs | |
| State | Published - 1999 |
| Event | Proceedings of the 1999 MRS Spring Meeting - Symposium on 'Materials Reliability in Microelectronics IX' - San Francisco, CA, United States Duration: Apr 6 1999 → Apr 8 1999 |