Facilities
Highlights
ASM America Low-Pressure Chemical Vapor Deposition System
Some Process Data Here (pdf file)
Temple-Boyer et. al. paper: LPCVD Nitride Stress (pdf)
Description:
The ASM LPCVD system has four tubes for the deposition of various thin films, including silicon nitride, polycrystalline silicon, and low temperature oxide (LTO). Wafers 4" and smaller can be accommodated.
Si3N4 is deposited at ~800C 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 with or without phosphine doping. Doped LTO is also called PSG, or phosphosilicate glass. The oxide deposition rate is mostly dependent on the temperature and is ~175Å/min.