Application of conductive atomic force microscopy to study the in-line electrical defects

Abstract

Selection of optimized electron beam parameters for in-line monitoring is necessary to eliminate false signals. Application of electron beam to detect electrical defects, particularly leakages, for static random access memory (SRAM) cells poses a great challenge as it requires current measurement tool with nanometer resolution to complement it. By correlating the brightness intensity or the gray-level value to the measured current values, we have shown that conductive atomic force microscopy (C-AFM) can overcome this obstacle and can be used to verify the validity of the voltage contrast (VC) captured by HMI eScan3xx Ebeam inspection tool.

Electrical characteristics of leakage issues caused by defective Ni salicide

“…If required, conventional layer-by-layer deprocessing until contact (CA) level and inspection by scanning electron microscope (SEM) were first done on the devices. At CA level, electrical analysis was then carried out by either conductive atomic force microscopy (C-AFM) or nanoprobing to extract the electrical characteristics [6][7].…”