Title :
An investigation of process dependence of porous IMD TDDB
Author :
Zhang, W.Y. ; Silvestre, M.C. ; Selvam, A. ; Ramanathan, E. ; Ordonio, C. ; Schaller, J. ; Shen, T. ; Yeap, K.B. ; Capasso, C. ; Justison, P. ; Lee, J.H.
Author_Institution :
GLOBALFOUNDRIES Inc., Malta, NY, USA
Abstract :
Process sensitivity of IMD TDDB in a vertical natural capacitor (VNCAP) structure was evaluated in this paper. Among others, CMP slurry and wet clean chemical were found to have higher level of interaction impacting TDDB performance. This enables proper process optimizations, such as reduction in the Cu+ concentration on ULK top surface. Additionally, dependence of the structure was analyzed and the top metal layer is identified as the weakest link in VNCAP failure. A solution for this was described and it involves accelerated thermal cure step which successfully recovered dielectric electric strength.
Keywords :
capacitors; chemical mechanical polishing; copper; electric breakdown; electric strength; etching; low-k dielectric thin films; porous materials; slurries; CMP slurry; Cu; Cu+ concentration; dielectric electric strength; porous IMD TDDB; process dependence; process sensitivity; time-dependent dielectric breakdown; vertical natural capacitor structure; wet clean chemical; Chemicals; Degradation; Dielectrics; Metals; Reliability; Slurries; Surface treatment; CMP; IMD TDDB; TDDB; ULK; VNCAP; VRDB;
Conference_Titel :
Reliability Physics Symposium (IRPS), 2015 IEEE International
Conference_Location :
Monterey, CA
DOI :
10.1109/IRPS.2015.7112819
