Selective Nanoscale Fabrication with Roughness Reduction of Polycrystalline Silicon by Physically Induced Fluorine Bonds Using Atomic Force Microscope

Abstract

Polycrystalline silicon (poly‐Si) is widely used as a gate layer in integrated circuits, transistors, and channels through nanofabrication. Nanoremoval and roughness control are required for nanomanufacturing of various electronic devices. Herein, a nanoscale removal method is developed to overcome the limitations of microcracks, complex procedures, and time‐consuming conventional fabrication and lithography methods. The method is implemented with a mechanically induced poly‐Si phase transition using atomic force microscope (AFM). Mechanical force induces the covalent bonds between silicon and fluorine atoms which cause the phase transition of poly‐Si. Then, the bond structure of the Si molecules is weakened and selectively removed by nano‐Newton‐scale force using AFM. A selective nanoscale removal with roughness control is implemented in 0.5 mM TBAF solution after mechanical force (43.58–58.21 nN) is applied. By the magnitude of nano‐Newton force, the removal depth of poly‐Si is controlled from 2.66 to 21.52 nm. Finally, the nanoscale fabrication on poly‐Si wafer is achieved. The proposed nanoremoval mechanism is a simple fabrication method that provides selective, nanoscale, and highly efficient removal with roughness control.