Specific Process Knowledge/Thin film deposition/Furnace LPCVD TEOS

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LPCVD (Low Pressure Chemical Vapor Deposition) TEOS

At the moment there is one furnace for TEOS oxide depositions at Danchip. The furnace is a Tempress horizontal furnace. The process is a batch process meaning you can run a batch of 10 wafers at a time. The deposition takes place at temperatures of 725 degrees Celsius. The reactive gases are dinitrogenoxide and silane. The LPCVD TEOS has a excellent step coverage and extreamly good for trench filling and the film thickness is very uniform over the wafer. We have two standard LPCVD TEOS processes: One that opens slowly for depositing thick layers (>750nm) and one for deposition of thin layers that opens faster. To get information on how to operate the furnace please read the manual which is uploaded to LabManager. Remember to anneal the TEOS oxide to improve the electrical properties as well as chemical resistance.

Process Knowledge

Please take a look at the process side for deposition of TEOS oxide: Deposition of Silicon Nitride using LPCVD

A rough overview of the performance of LPCVD Silicon Nitride and some process related parameters

Purpose	Deposition of TEOS silicon oxide	Deposition of silicon oxide on silicon nitride Deposition of silicon oxide on structured surfaces, eg. to cover holes or sealing small cavities.
Performance	Film thickness	Si₃N₄:~50Å - ~3000Å SRN: ~50Å - ~10000Å
.	Step coverage	Good
.	Film quality	Dense film Few defects
Process parameter range	Process Temperature	800-835 ^oC
.	Process pressure	80-230 mTorr
.	Gas flows	SiH $_{2}$ Cl $_{2}$ :10-100 sccm NH $_{3}$ :10-75 sccm
Substrates	Batch size	1-25 4" wafer per run Deposition on both sides of the substrate
.	Substrate material allowed	Silicon wafers (new from the box or RCA cleaned) with layers of silicon oxide or silicon (oxy)nitride (RCA cleaned) Quartz wafers (RCA cleaned)