Specific Process Knowledge/Thin film deposition/Furnace LPCVD PolySilicon: Difference between revisions

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-==Overview of the performance of LPCVD Silicon Nitride and some process related parameters==
+==Overview of the performance of the LPCVD polysilicon processes and some process related parameters==
 {| border="2" cellspacing="0" cellpadding="10"
 |-
 !style="background:silver; color:black;" align="left"|Purpose
-|style="background:LightGrey; color:black"|Deposition of silicon nitride
+|style="background:LightGrey; color:black"|Deposition of LPCVD polysilicon
-|style="background:WhiteSmoke; color:black"|Stoichiometry:
+|style="background:WhiteSmoke; color:black"|
-*Si<sub>3</sub>N<sub>4</sub>
+" furnace:
-*SRN
+*Standard polySi
-SRN: Silicon Rich Nitride
+*Amorphous polySi
+*Boron doped polySi (BCl<math>_3</math> dopant)
+" furnace:
+*Standard polySi
+*Amorphous polySi
+*Boron doped polySi (B<math>_2</math>H<math>_6</math> dopant)
+*Phosphorus doped polySi
 |-
 !style="background:silver; color:black" align="left" valign="top" rowspan="3"|Performance
 |style="background:LightGrey; color:black"|Film thickness
 |style="background:WhiteSmoke; color:black"|
-*Si<sub>3</sub>N<sub>4</sub>:~50Å - ~3000Å
+" furnace:
-*SRN: ~50Å - ~10000Å
+*Standard polySi: 0-2000 nm
+*Amorphous polySi: 0-1000 nm
+*Boron doped polySi: 0-1000 nm
+" furnace
+*Standard polySi: 0-2000 nm
+*Amorphous polySi: 0-2000 nm
+*Boron doped polySi: 0-2000 nm
+*Phosphorus doped polySi: 0-1000 nm
 |-
 |style="background:LightGrey; color:black"|Step coverage
@@ Line 39: / Line 52: @@
 *Good
 |-
-|style="background:LightGrey; color:black"|Film quality
+|style="background:LightGrey; color:black"|Thickness uniformity
 |style="background:WhiteSmoke; color:black"|
-*Dense film
+*Good
-*Few defects
 |-
 !style="background:silver; color:black" align="left" valign="top" rowspan="3"|Process parameter range
 |style="background:LightGrey; color:black"|Process Temperature
 |style="background:WhiteSmoke; color:black"|
-*800-835 <sup>o</sup>C
+" furnace:
+*Standard polySi: 620 <sup>o</sup>C
+*Amorphous polySi: 560-580 <sup>o</sup>C
+*Boron doped polySi: 600-620 <sup>o</sup>C
+Note: The process temperature depends vary over the furnace tube
+" furnace:
+*Standard polySi: 620 <sup>o</sup>C
+*Amorphous polySi: 560-580 <sup>o</sup>C
+*Boron doped polySi: 620 <sup>o</sup>C
+*Phosphorus doped polySi: 620 <sup>o</sup>C
+The process temperature depends vary over the furnace tube
 |-
 |style="background:LightGrey; color:black"|Process pressure
 |style="background:WhiteSmoke; color:black"|
-*80-230 mTorr
+*150-250 mTorr
+The process pressure depends on the actual process
 |-
 |style="background:LightGrey; color:black"|Gas flows
 |style="background:WhiteSmoke; color:black"|
-*SiH<math>_2</math>Cl<math>_2</math>:10-100 sccm
+" furnace:
-*NH<math>_3</math>:10-75 sccm
+*SiH<math>_4</math>: 50-70 sccm
+*BCl<math>_1</math>: 1 sccm
+The silane (SiH<math>_4</math>) flow depends on the actual process
+" furnace:
+*SiH<math>_4</math>: 80 sccm
+*B<math>_2</math>H<math>_6</math>: 7 sccm
+*PH<math>_1</math>: 7 sccm
 |-
 !style="background:silver; color:black" align="left" valign="top" rowspan="2"|Substrates
 |style="background:LightGrey; color:black"|Batch size
 |style="background:WhiteSmoke; color:black"|
-*1-25 4" wafer per run
+" furnace:
-*Deposition on both sides of the substrate
+*1-25 4" wafers or 6" wafers per run
+*1-30 4" wafers per run
+Deposition on both sides of the substrate
 |-
-| style="background:LightGrey; color:black"|Substrate material allowed
+| style="background:LightGrey; color:black"|Substrate materials allowed
 |style="background:WhiteSmoke; color:black"|
-*Silicon wafers (new from the box or RCA cleaned)
+*Silicon wafers (new from a clean box or RCA cleaned)
-**with layers of silicon oxide or silicon (oxy)nitride (RCA cleaned)
+**with layers of silicon oxide or silicon (oxy)nitride
 *Quartz wafers (RCA cleaned)
 |-
 |}