Field Dependence of Porous Low-$k$ Dielectric Breakdown as Revealed by the Effects of Line Edge Roughness on Failure Distributions

Abstract

We investigate the electric field (E) dependence of the breakdown of porous low-k dielectrics by measuring the changes in the failure time distribution resulting from the presence of line edge roughness. We show that the Weibull β increases with decreasing field, clearly demonstrating that dielectric breakdown does not exhibit 1/E or E −n characteristics.Index Terms-Cu/low-k interconnect reliability, line edge roughness (LER), time-dependent dielectric breakdown (TDDB).

Reliability limitations to the scaling of porous low-k dielectrics

“…The field dependence f(E ILD ) remains controversial despite intense recent scrutiny [5,[13][14][15][16]. Our recent work on the distortion of failure distributions from Weibull due to LER suggests that the field dependence must be of the E-or √E-model [17]. Therefore, in this study we use a √E field model for the failure distribution modeling study since recent experimental evidence tends to support this functionality [18].…”