Low Pressure Chemical Vapor Deposition (LPCVD) system is used for deposition of poly-silicon, and silicon nitride layers. In this process, at a specified temperature and pressure and in the presence of reactive gases, the desired layer is deposited on the silicon substrate surface. In this process, by injection of reactive gases into the chamber and increasing temperature, the gases are decomposed on the substrate surface and consequently produce the desired layer.
Deposition of poly-silicon layer for the gate of field-effect transistors, and fabrication of silicon nitride membranes are some of the main applications of this system. Furthermore, relying on developed processes by the INEC researchers, silicon nanowires, silicon nanotubes and Bilayer nanotubes can be synthesized.
The device maximum working temperature and minimum pressure are 850 °C and 0.001 Torr, respectively; and the input gases are silane, hydrogen, ammonia, argon and nitrogen. Gas flow, pressure and temperature are controllable in this system. The maximum thickness of deposited layer is 1 micron.