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

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.