Kinetics of copper drift in PECVD dielectrics |
| |
Authors: | Loke A.L.S. Changsup Ryu Yue C.P. Cho J.S.H. Wong S.S. |
| |
Affiliation: | Center for Integrated Syst., Stanford Univ., CA ; |
| |
Abstract: | We quantified the drift of Cu ions into various PECVD dielectrics by measuring shifts in capacitance-voltage behavior after subjecting Cu-gate MOS capacitors to bias-temperature stress. At a field of 1.0 MV/cm and temperature of 100°C, Cu ions drift readily into PECVD oxide with a projected accumulation of 2.7×1013 ions/cm 2 after 10 years. However, in PECVD oxynitride, the projected accumulation under the same conditions is only 2.3×1010 ions/cm2. These findings demonstrate the necessity of integrating drift barriers, such as PECVD oxynitride layers, in Cu interconnection systems to ensure threshold stability of parasitic field n-MOS devices |
| |
Keywords: | |
|
|