A new method to characterize dopant profiles in NMOSFETs using conventional transmission electron microscopy

We have developed a new method using conventional transmission electron microscopy (TEM) to obtain two dimensional dopant profiles in silicon and applied it to 40 nm-gate-length N ⁺ /p metal oxide semiconductor field effect transistors (MOSFETs). The results are consistent with those of selective-chemically etched samples observed by TEM. This method, using focused ion beam (FIB) sample preparation and conventional TEM, has the great advantage of simple sample preparation and high spatial resolution compared to other characterization methods, such as atomic capacitance microscopy, spreading resistance microscopy, and TEM combined with selective chemical etching. This indicates that this method can be applicable to the analysis of FETs at the 65 nm or smaller node.