Effect of Hydrophobicity and Surface Potential of Silicon on SiO<sub>2</sub> Etching in Nanometer-Sized Narrow Spaces

Wet etching in nanometer-sized three-dimensional spaces creates new challengesbecause of the scaling of semiconductor devices with complex 3D architecture. Wet etching withinspaces is affected by the mass transport of the etchant ions that are impacted by the hydrophobicityand surface potential of surface. However, the kinetics of chemical reactions within the spaces is stillunclear.In this paper, we studied the effect of hydrophobicity and surface potential of silicon surface on SiO2etching in nanometer-sized narrow spaces by adding various additive components to etching solutions.We found that the transport of etchant ions into narrow spaces is governed by controlling thehydrophobicity and surface potential of the confined system walls.