Low Pressure Chemical Vapor Deposition

We have three furnaces dedicated to LPCVD of the following films:

  • Silicon Dioxide: The process is utilizing diethylsilane and oxygen to deposit SiO2 layers at 410oC.
    • On 6" wafers, the deposition rate is ~ 5.1 nm/min.  The flow rates for O2 and DES are 200 and 100 sccm respectively.  The deposition pressure is 600 mTorr.
    • We currently do not have a boat to deposit on 4" wafers, we use the 6" boat but the uniformity is not as good.
  • Silicon Nitride: The process is utilizing ammonia (NH3) and dichlorosilane (SiH2Cl2) to deposit Si3N4 layers at 800oC.
    • On 4" wafers, the deposition rate is ~ 4.7 nm/min with better than 4% uniformity. The flow rates for SiH2Cl2 and NH3 are 40 and 120 sccm respectively giving a total pressure of 300 mTorr.
    • On 6" wafers, the deposition rate is ~ 2.5 nm/min with better than 4% uniformity. The flow rates for SiH2Cl2 and NH3 are 79 and 260 sccm respectively giving a total pressure of 300 mTorr.
  • Amorphous Silicon: The process is utilizing disilane (Si2H6) to deposit Si films at 565oC.
    • On 4" wafers, the deposition rate is ~ 4 nm/min with better than 2.5% uniformity. The flow rate for Si2H6 is 60 sccm, the deposition pressure is 160 mTorr.
    • On 6" wafers, we do not have recent data to report.
  • Polycrystalline Silicon: The process is utilizing disilane (Si2H6) to deposit Si films at 635oC.
    • On 4" wafers, the deposition rate is ~ 5.8 nm/min with better than 2% uniformity. The flow rate for Si2H6 is 60 sccm, the deposition pressure is 160 mTorr.
    • On 6" wafers, the deposition rate is ~ 5.2 nm/min with better than 2.5% uniformity. The flow rate for Si2H6 is 60 sccm, the deposition pressure is 160 mTorr.