Comparative Study of 3D Measurement Techniques (SPM, SEM, TEM) for Submicron Structures

Non destructive measurements are of great interest in 3D metrology (contact holes, grating structures and resist profiles). Conventional measurement techniques to obtain 3D information are SEM and TEM cross section, but are destructive. In this report a comparative study is presented between SPM, SEM and TEM. Simulations and measurements indicate that the tip shape is the limiting factor for using SPM as a 3D measurement tool. Pitch and height can be measured accurately with SPM, provided good calibration. Linewidth measurements show a dead zone, depending on tip geometry.