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 410^oC.
  • 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 800^oC.
  • 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 565^oC.
  • 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 635^oC.
  • 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.