Measurement of the Stability and Investigation of the Rupture Behavior of Semiconductor Line Nanostructures by AFM

Abstract

The measured lateral stability of polysilicon line structures on a Silicon Oxy-Nitride layer is presented. This has been measured by Lateral Force Microscopy (LFM) in order to understand how much force can be applied to the structure during a wet cleaning process with subsequent drying. The measured values in the lateral dimension are between 2 and 5 µN which is in the same range as expected by mechanical calculations. SEM micrographs of the damaged sites confirm a round breaking shape. The length of the broken line is around 0.5 to 1 µm with a lower limit of 0.5 µm which is similar to previously reported results on real damage produced by cleaning processes supported with Megasonic energy. The rupture in the AFM experiments occurs clearly in the polysilicon and not at the interfaces of the structure.