COMBINATIONAL LOGIC ANALYSIS WITH LASER VOLTAGE PROBING

摘要

As technologies scale, integrated circuits (ICs) now have incredibly dense transistor packing that can fail due to miniscule defects, which require electrical fault isolation (EFI). Of several available EFI techniques, laser voltage probing (LVP) and derivatives (such as LVx) using continuous-wave near-infrared laser are very popular. The operating principle of LVx is that the absorption of light gets modulated by changes in the electrical field and the free carrier (plasma) density within a transistor as it switches. The fault isolation precision of these tools ultimately depends on the resolution of the optical probe.