For improving the three-dimensional structure of phase-change memory devices, Ovonic threshold switch devices have received renewed attention as selectors owing to a simple production process, good scalability, and excellent performance. It can replace transistors and diodes in the available technology. In this article, we studied the GeSe-based chemical mechanical polishing process. The different concentrations of hydrogen peroxide and lysine interacting with GeSe in chemical mechanical polishing were investigated. Material characterization was performed by scanning electron microscopy and atomic force microscopy. In addition, the reaction mechanism in the chemical mechanical polishing process was analyzed by electrochemical experiments and X-ray photoelectron spectroscopy.

The investigation of the chemical effect of slurry pH on the CMP process of a C-GST film through electrochemical means reveals a conversion of polishing behavior from the cycling to mechanical mechanism as the pH level varies.

Titanium nitride (TiN) is preferred for use as the bottom electrode contact due to its excellent thermal stability and suitable electrical conductivity. We have studied the effect of using potassium permanganate (KMnO4), L-Aspartic Acid (L-Asp) and alumina abrasives as slurry in chemical mechanical polishing (CMP) of TiN film. Different concentrations of potassium permanganate and different concentrations of L-aspartic acid additives were applied to the CMP of TiN. The results show that KMnO4 and L-Asp can increase removal rate and improve the surface smoothness of TiN. The removal mechanism of TiN was analyzed by XPS and electrochemical tests, and the TiN film was characterized by atomic force microscope and scanning electron microscope.