Specific Process Knowledge/Thin film deposition/Furnace LPCVD PolySilicon: Difference between revisions
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Ikke skrevet! | |||
==LPCVD (Low Pressure Chemical Vapor Deposition) PolySilicon== | |||
[[Image:A4_Furnace_PolySi.jpg|300x300px|thumb|A4 Furnace PolySilicon: positioned in cleanroom 2]] | [[Image:A4_Furnace_PolySi.jpg|300x300px|thumb|A4 Furnace PolySilicon: positioned in cleanroom 2]] | ||
At the moment there is one furnace for PolySilicon depositions at Danchip. The furnace is a Tempress horizontal furnace. The process is a batch process meaning you can run a batch of 25 wafers at a time. The deposition takes place at temperatures of 800-835 degrees Celsius. The reactive gases are Ammonia and dichlorsilane. The LPCVD nitride has a good step coverage and the film thickness is very uniform over the wafer. We have two standard LPCVD nitride processes: One for depositing stoichiometric nitride (Si<sub>3</sub>N<sub>4</sub>) and one for deposition of low stress nitride (SNR). To get information on how to operate the furnace please read the manual which is uploaded to LabManager. | |||
==Process Knowledge== | |||
Please take a look at the process side for deposition of Silicon Nitride using LPCVD: | |||
[[Specific Process Knowledge/Thin film deposition/Deposition of Silicon Nitride/Deposition of Silicon Nitride using LPCVD|Deposition of Silicon Nitride using LPCVD]] | |||
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==A rough overview of the performance of LPCVD Silicon Nitride and some process related parameters== | |||
{| border="2" cellspacing="0" cellpadding="10" | |||
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!style="background:silver; color:black;" align="left"|Purpose | |||
|style="background:LightGrey; color:black"|Deposition of silicon nitride ||style="background:WhiteSmoke; color:black"|Stoichiometry: | |||
*Si<sub>3</sub>N<sub>4</sub> | |||
*SRN | |||
SRN: Silicon Rich Nitride | |||
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!style="background:silver; color:black" align="left"|Performance | |||
|style="background:LightGrey; color:black"|Film thickness||style="background:WhiteSmoke; color:black"| | |||
*Si<sub>3</sub>N<sub>4</sub>:~50Å - ~3000Å | |||
*SRN: ~50Å - ~10000Å | |||
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|style="background:silver; color:black"|.||style="background:LightGrey; color:black"|Step coverage | |||
|style="background:WhiteSmoke; color:black"| | |||
*Good | |||
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|style="background:silver; color:black"|.||style="background:LightGrey; color:black"|Film quality | |||
|style="background:WhiteSmoke; color:black"| | |||
*Dense film | |||
*Few defects | |||
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!style="background:silver; color:black" align="left"|Process parameter range | |||
|style="background:LightGrey; color:black"|Process Temperature | |||
|style="background:WhiteSmoke; color:black"| | |||
*800-835 <sup>o</sup>C | |||
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|style="background:silver; color:black"|.||style="background:LightGrey; color:black"|Process pressure | |||
|style="background:WhiteSmoke; color:black"| | |||
*80-230 mTorr | |||
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|style="background:silver; color:black"|.||style="background:LightGrey; color:black"|Gas flows | |||
|style="background:WhiteSmoke; color:black"| | |||
*SiH<math>_2</math>Cl<math>_2</math>:10-100 sccm | |||
*NH<math>_3</math>:10-75 sccm | |||
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!style="background:silver; color:black" align="left"|Substrates | |||
|style="background:LightGrey; color:black"|Batch size | |||
|style="background:WhiteSmoke; color:black"| | |||
*1-25 4" wafer per run | |||
*Deposition on both sides of the substrate | |||
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|style="background:silver; color:black"|.|| style="background:LightGrey; color:black"|Substrate material allowed | |||
|style="background:WhiteSmoke; color:black"| | |||
*Silicon wafers (new from the box or RCA cleaned) | |||
**with layers of silicon oxide or silicon (oxy)nitride (RCA cleaned) | |||
*Quartz wafers (RCA cleaned) | |||
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