System for Monitoring the Process of Reactive Ion Etching of Silicon for Nanostructure Fabrication

A control system for the laser interferometer for the reactive ion etching setup was developed. A series of chips with the same structure were fabricated for precise calibration of the upper silicon layer of the silicon-on-insulator material etching rate. The thickness of the structure on each chip varied depending on the etching time. The height of the resulting steps was measured using the semicontact mode of an atomic force microscope. For the etching regime in CF4 and O2 gas plasma (flow ratio 20:5, pressure 4 Pa, power 40 W), the silicon etching rate is 0.31 ±0.1 nm/s. The adduce parameters allow stopping silicon etching at a depth of ∼5 to 120 nm with an accuracy of no worse than 2 nm. The obtained results make allow to solve a number of problems in creating various nanoelectronic devices. In particular, in silicon nanowires creation, processes of thermal oxidation and subsequent washing of the oxide of the unetched structure are used very often and leads to a significant improvement in the transistor channels characteristics.