CVD Firstnano Low-Pressure Chemical Vapor Deposition System
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
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)