EPFL PVAC HiVacuum KelvinProbeForceMicroscopy Resistance BTO China Mapping MESA structure Sidewall SRAM light_emitting Hafnium_dioxide TungstenDeposition SICM FailureAnalysis Silver Electronics PS_PVAC Gallium_Arsenide Sphere fluoroalkane LeakageCurrent food Pinpoint PFM plastics multi_layer Nanotechnology SPMLabs 3-hexylthiophene ULCA Conduct StrontiumTitanate KAIST WS2