CVD Firstnano Low-Pressure Chemical Vapor Deposition System
The Firstnano Easy Tube LPCVD system has three tubes for the deposition of silicon nitride, polycrystalline silicon, and low temperature oxide (LTO). Wafers 6" and smaller can be accommodated.
Currently only clean bare silicon or quartz wafers are allowed in the LPCVD.
Si3N4 is deposited at ~825C and low pressure (~250 mtorr) using dichlorosilane (SiCl2H2) and ammonia (NH3). The deposition rate is 25-35 Å/min.
Polycrystalline silicon (or poly-Si) is deposited at a low pressure (~200 mtorr) using silane (SiH4). Deposition temperature is ~620C for polysilicon and ~560C for amorphous silicon. The deposition rate for poly silicon is 40 – 160 Å/min.
Silicon dioxide (SiO2) is deposited at between 400C and 470C, at low pressure (150 - 350 mtorr), from silane and oxygen. The oxide deposition rate is mostly dependent on the temperature and is ~175Å/min.
Some Process Data Here (pdf file)
Temple-Boyer et. al. paper: LPCVD Nitride Stress (pdf)