Application of Electro Optical Terahertz Pulse Reflectometry for Fault Localization and Defect Analysis

Electro Optical Terahertz Pulse Reflectometry (EOTPR) is an E-FA (Electrical Failure Analysis) technique in the semiconductor industry for non-destructive electrical fault isolation for shorts, leakages and opens. This paper introduces the capability and presents several case studies identifying the physical location of defects where EOTPR is useful as a non-destructive analysis technique. In this paper, the methodology and application of EOTPR on open and short failure isolations in advanced 2.5D IC and wafer level packages (WLP) have been presented. The experimental results of P-FA (Physical Failure Analysis) verify the accuracy of the EOTPR system in determining the distance to defect.