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.

Ellipsometric study of the polysilicon/thin oxide/single-crystalline silicon structure and its change upon annealing

No abstract

No abstract

Enhanced particle removal processes in wet cleaning of semiconductor wafers can cause significant lateral forces on surface structures. These forces have to be limited to below the stability of the (nano) structures on the surface to prevent damage. A mechanical fracture test based on atomic force microscope manipulation was used in liquid media (deionized water, isopropanol, and propylene carbonate) to measure the lateral stability of polysilicon line structures. The results are compared to previously reported results in air. All liquid media investigated here showed a stabilizing effect. Maximum stability was found for immersion in isopropanol. The size of the damage generated was mainly influenced by the viscosity of the liquids. The results do not support a stress corrosion cracking process.