Comprehensive study of effective current variability and MOSFET parameter correlations in 14nm multi-fin SOI FINFETs

摘要

A first time rigorous experimental study of effective current (I_eff) variability in high-volume manufacturable (HVM) 14nm Silicon-On-Insulator (SOI) FINFETs is reported which identifies, threshold voltage (Vtlin), external resistance (Rext), and channel trans-conductance (Gm) as three independent sources of variation. The variability in Gm, Vtlin (A_VT=1.4(n)/0.7(p) mV-μm), and Ieff exhibit a linear Pelgrom fit indicating local variations, along with non-zero intercept which suggests the presence of global variations at the wafer level. Relative contribution of Gm to Ieff variability is dominant in FINFETs with small number of fins (Nfin); however, both Gm and Rext variations dominate in large Nfin devices. Relative contribution of Vtlin remains almost independent of Nfin. Both n and p FINFETs show the above mentioned trends.