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

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Ikke skrevet!
'''Feedback to this page''': '''[mailto:thinfilm@nanolab.dtu.dk?Subject=Feed%20back%20from%20page%20http://labadviser.nanolab.dtu.dk/index.php/Specific_Process_Knowledge/Thin_film_deposition/Furnace_LPCVD_PolySilicon) click here]'''
==LPCVD (Low Pressure Chemical Vapor Deposition) PolySilicon==
[[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.
<i> Unless otherwise stated, this page is written by <b>DTU Nanolab internal</b></i>


==Process Knowledge==
[[Category: Equipment|Thin film LPCVD Poly]]
Please take a look at the process side for deposition of Silicon Nitride using LPCVD:
[[Category: Furnaces|LPCVD Poly]]
[[Specific Process Knowledge/Thin film deposition/Deposition of Silicon Nitride/Deposition of Silicon Nitride using LPCVD|Deposition of Silicon Nitride using LPCVD]]
[[Category: Thin Film Deposition|LPCVD Poly]]
<br clear="all" />




==A rough overview of the performance of LPCVD Silicon Nitride and some process related parameters==
==Deposition of silicon using LPCVD==
[[Image:A4_Furnace_PolySi.jpg|300x300px|thumb|4" polysilicon furnace (B4) located in cleanroom B-1]]
[[Image:E2.JPG|300x300px|thumb|6" polysilicon furnace located (E2) in cleanroom E-6]]


{| border="2" cellspacing="0" cellpadding="10"  
DTU Nanolab has two furnaces for deposition of LPCVD (Low Chemical Vapour Deposition) silicon: A 6" furnace (installed in 2011) for deposition of standard polySi, amorphous Si and boron doped polySi on 100 mm or 150 mm wafers and a 4" furnace (installed in 1995) for deposition of standard polySi, amorphous Si, boron- and phosphorous doped polySi on 100 mm wafers. In LabManager the two furnaces are named "Furnace: LPCVD Poly-Si (4") (B4)" and "Furnace: LPCVD Poly-Si (6") (E2)", respectively. Both furnaces are Tempress horizontal furnaces.
 
The LPCVD silicon deposition is a batch process, where silicon is deposited on a batch of 25 or 50 wafers (6" polySi furnace) or 30 wafers (4" polySi furnace). The silicon has a good step coverage, and especially for standard polySi the film thickness is very uniform over the wafers.
 
The reactive gas is silane (SiH<sub>4</sub>). The dopant for boron doped polySi is BCl<sub>3</sub> - only available at request (6" polySi furnace) or B<sub>2</sub>H<sub>6</sub> (4" polySi furnace), and for phosphorous doped polySi the dopant is PH<sub>3</sub> (4" polySi furnace). For standard and doped polysilion the deposition takes place at a temperature of 600 <sup>o</sup>C - 620 <sup>o</sup>C and a pressure of 200-250 mTorr. For amorphous silicon the deposition temperature is lower, and thus the deposition rate is also lower. For phosphorus doped polySi the deposition rate is approximately ten times lower than for standard and boron doped polySi. Please check the cross contamination information in LabManager before you use any of the two furnaces.
 
 
'''The user manuals, quality control procedures and results, technical information and contact information can be found in LabManager:'''
 
'''[http://www.labmanager.dtu.dk/function.php?module=Machine&view=view&mach=86 4" LPCVD polysilicon furnace (B4)]'''
 
'''[http://www.labmanager.dtu.dk/function.php?module=Machine&view=view&mach=291 6" LPCVD polysilicon furnace (E2)]'''
 
'''[https://labmanager.dtu.dk/d4Show.php?id=1926 Furnace computer manual]'''
 
 
== Manual for the furnace computer to the A, B, C and E stack furnaces ==
 
The A, B, C and E stack furnaces can be controlled either from a touch screen by each furnace or from a furnace computer. The user manual for the furnace computer can be found here:
 
[[media:Furnace_computer_manual.pdf|Manual for furnace computers for the A, B, C and E stack furnaces]]
 
==Process information==
 
*[[Specific_Process_Knowledge/Thin_film_deposition/Deposition_of_polysilicon/Deposition_of_polysilicon_using_LPCVD/Standard_recipes,_QC_limits_and_results_for_the_4%22_polysilicon_furnace|Deposition of polysilicon using the 4" polysilicon furnace]]
*[[/Boron doped poly-Si and a-Si |Boron doped poly-Si and a-Si by using 4" polysilicon furnace]]
 
 
*[[Specific_Process_Knowledge/Thin_film_deposition/Deposition_of_polysilicon/Deposition_of_polysilicon_using_LPCVD/Standard_recipes,_QC_limits_and_results_for_the_6%22_polysilicon_furnace|Deposition of polysilicon using the 6" polysilicon furnace]]
*[[/Boron doped poly-Si |Boron doped poly-Si using 6" polysilicon furnace]]
 
<!-- hide text
*[[Specific Process Knowledge/Thin film deposition/Deposition of polysilicon/Deposition of polysilicon using LPCVD|Deposition of polysilicon using LPCVD]]
hide text -->
 
==Overview of the performance of the LPCVD polysilicon processes and some process related parameters==
 
{| border="2" cellspacing="0" cellpadding="2"
 
!colspan="2" border="none" style="background:silver; color:black;" align="center"|Equipment
|style="background:WhiteSmoke; color:black"|<b>4" LPCVD polysilicon furnace (B4)</b>
|style="background:WhiteSmoke; color:black"|<b>6" LPCVD polysilicon furnace (E2)</b>
|-
|-
!style="background:silver; color:black;" align="left"|Purpose  
!style="background:silver; color:black;" align="center"|Purpose  
|style="background:LightGrey; color:black"|Deposition of silicon nitride ||style="background:WhiteSmoke; color:black"|Stoichiometry:
|style="background:LightGrey; color:black"|Deposition of  
*Si<sub>3</sub>N<sub>4</sub>
|style="background:WhiteSmoke; color:black"|
*SRN
*Standard polySi
SRN: Silicon Rich Nitride
*Amorphous polySi
*Boron doped polySi (B<sub>2</sub>H<sub>6</sub> dopant)
*Phosphorus doped polySi (PH<sub>3</sub> dopant)
|style="background:WhiteSmoke; color:black"|
*Standard polySi
*Amorphous polySi
*Boron doped polySi (BCl<sub>3</sub> dopant)
|-
|-
!style="background:silver; color:black" align="left"|Performance
!style="background:silver; color:black" align="center" valign="center" rowspan="2"|Performance
|style="background:LightGrey; color:black"|Film thickness||style="background:WhiteSmoke; color:black"|
|style="background:LightGrey; color:black"|Step coverage
*Si<sub>3</sub>N<sub>4</sub>:~50Å - ~3000Å
|style="background:WhiteSmoke; color:black"|
*SRN: ~50Å - ~10000Å
*Very Good
|style="background:WhiteSmoke; color:black"|
*Very good
|-
|-
|style="background:silver; color:black"|.||style="background:LightGrey; color:black"|Step coverage
|style="background:LightGrey; color:black"|Film quality
|style="background:WhiteSmoke; color:black"|
|style="background:WhiteSmoke; color:black"|
*Good
*Deposition on both sides of the substrate
|-
*Good uniformity over the wafer
|style="background:silver; color:black"|.||style="background:LightGrey; color:black"|Film quality
|style="background:WhiteSmoke; color:black"|
|style="background:WhiteSmoke; color:black"|
*Dense film
*Deposition on both sides of the substrate
*Few defects
*Good uniformity over the wafer
|-
|-
!style="background:silver; color:black" align="left"|Process parameter range
!style="background:silver; color:black" align="center" valign="center" rowspan="3"|Process parameter range
|style="background:LightGrey; color:black"|Process Temperature
|style="background:LightGrey; color:black"|Process Temperature
|style="background:WhiteSmoke; color:black"|
|style="background:WhiteSmoke; color:black"|
*800-835 <sup>o</sup>C
*Standard polySi: 620 <sup>o</sup>C
*Amorphous polySi: 560-580 <sup>o</sup>C
*Boron doped a-Si: 580 <sup>o</sup>C
*Phosphorus doped a-Si: 580 <sup>o</sup>C
*Boron doped polySi: 620 <sup>o</sup>C
*Phosphorus doped polySi: 620 <sup>o</sup>C
|style="background:WhiteSmoke; color:black"|
*Standard polySi: 620 <sup>o</sup>C
*Amorphous polySi: 560-580 <sup>o</sup>C
*Boron doped polySi: 600-620 <sup>o</sup>C
 
The process temperature vary over the furnace tube
|-
|-
|style="background:silver; color:black"|.||style="background:LightGrey; color:black"|Process pressure
|style="background:LightGrey; color:black"|Process pressure
|style="background:WhiteSmoke; color:black"|
*200-250 mTorr
|style="background:WhiteSmoke; color:black"|
|style="background:WhiteSmoke; color:black"|
*80-230 mTorr
*150-220 mTorr
The process pressure depends on the process
|-
|-
|style="background:silver; color:black"|.||style="background:LightGrey; color:black"|Gas flows
|style="background:LightGrey; color:black"|Gas flows
|style="background:WhiteSmoke; color:black"|
|style="background:WhiteSmoke; color:black"|
*SiH<math>_2</math>Cl<math>_2</math>:10-100 sccm
*SiH<sub>4</sub>: 80 sccm
*NH<math>_3</math>:10-75 sccm
*B<sub>2</sub>H<sub>6</sub>: 7 sccm
*PH<sub>3</sub>: 7 sccm
|style="background:WhiteSmoke; color:black"|
*SiH<sub>4</sub>: 50-70 sccm
*BCl<sub>3</sub>: 1 sccm
The silane (SiH<sub>4</sub>) flow depends on the process
|-
|-
!style="background:silver; color:black" align="left"|Substrates
!style="background:silver; color:black" align="center" valign="center" rowspan="2"|Substrates
|style="background:LightGrey; color:black"|Batch size
|style="background:LightGrey; color:black"|Batch size
|style="background:WhiteSmoke; color:black"|
|style="background:WhiteSmoke; color:black"|
*1-25 4" wafer per run
*1-30 100 mm wafers
*Deposition on both sides of the substrate
Including a testwafer with ~110 nm oxide
|style="background:WhiteSmoke; color:black"|
*1-25 or 1-50 100 mm wafers
*1-25 or 1-50 150 mm wafers
Including a testwafer with ~110 nm oxide
|style="background:WhiteSmoke; color:black"|
|-
|-
|style="background:silver; color:black"|.|| style="background:LightGrey; color:black"|Substrate material allowed
| style="background:LightGrey; color:black"|Substrate materials allowed
|style="background:WhiteSmoke; color:black"|
|style="background:WhiteSmoke; color:black"|
*Silicon wafers (new from the box or RCA cleaned)
*Silicon wafers (new 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)
**from the A, B and E stack furnaces
*Quartz/fused silica wafers (RCA cleaned)
|style="background:WhiteSmoke; color:black"|
*Silicon wafers (new or RCA cleaned)
**with layers of silicon oxide or silicon (oxy)nitride
**from the A, B and E stack furnaces
*Quartz/fused silica wafers (RCA cleaned)
|-  
|-  
|}
|}
== Rules for storage and RCA cleaning of wafers to the B4 and E2 furnaces ==
*[[Specific_Process_Knowledge/Thermal_Process/Storage_and_cleaning_of_wafer_to_the_A,_B,_C_and_E_stack_furnaces|Storage and cleaning of wafer to the B4 and E2 furnaces]]

Latest revision as of 13:18, 26 June 2023

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Unless otherwise stated, this page is written by DTU Nanolab internal


Deposition of silicon using LPCVD

4" polysilicon furnace (B4) located in cleanroom B-1
6" polysilicon furnace located (E2) in cleanroom E-6

DTU Nanolab has two furnaces for deposition of LPCVD (Low Chemical Vapour Deposition) silicon: A 6" furnace (installed in 2011) for deposition of standard polySi, amorphous Si and boron doped polySi on 100 mm or 150 mm wafers and a 4" furnace (installed in 1995) for deposition of standard polySi, amorphous Si, boron- and phosphorous doped polySi on 100 mm wafers. In LabManager the two furnaces are named "Furnace: LPCVD Poly-Si (4") (B4)" and "Furnace: LPCVD Poly-Si (6") (E2)", respectively. Both furnaces are Tempress horizontal furnaces.

The LPCVD silicon deposition is a batch process, where silicon is deposited on a batch of 25 or 50 wafers (6" polySi furnace) or 30 wafers (4" polySi furnace). The silicon has a good step coverage, and especially for standard polySi the film thickness is very uniform over the wafers.

The reactive gas is silane (SiH4). The dopant for boron doped polySi is BCl3 - only available at request (6" polySi furnace) or B2H6 (4" polySi furnace), and for phosphorous doped polySi the dopant is PH3 (4" polySi furnace). For standard and doped polysilion the deposition takes place at a temperature of 600 oC - 620 oC and a pressure of 200-250 mTorr. For amorphous silicon the deposition temperature is lower, and thus the deposition rate is also lower. For phosphorus doped polySi the deposition rate is approximately ten times lower than for standard and boron doped polySi. Please check the cross contamination information in LabManager before you use any of the two furnaces.


The user manuals, quality control procedures and results, technical information and contact information can be found in LabManager:

4" LPCVD polysilicon furnace (B4)

6" LPCVD polysilicon furnace (E2)

Furnace computer manual


Manual for the furnace computer to the A, B, C and E stack furnaces

The A, B, C and E stack furnaces can be controlled either from a touch screen by each furnace or from a furnace computer. The user manual for the furnace computer can be found here:

Manual for furnace computers for the A, B, C and E stack furnaces

Process information



Overview of the performance of the LPCVD polysilicon processes and some process related parameters

Equipment 4" LPCVD polysilicon furnace (B4) 6" LPCVD polysilicon furnace (E2)
Purpose Deposition of
  • Standard polySi
  • Amorphous polySi
  • Boron doped polySi (B2H6 dopant)
  • Phosphorus doped polySi (PH3 dopant)
  • Standard polySi
  • Amorphous polySi
  • Boron doped polySi (BCl3 dopant)
Performance Step coverage
  • Very Good
  • Very good
Film quality
  • Deposition on both sides of the substrate
  • Good uniformity over the wafer
  • Deposition on both sides of the substrate
  • Good uniformity over the wafer
Process parameter range Process Temperature
  • Standard polySi: 620 oC
  • Amorphous polySi: 560-580 oC
  • Boron doped a-Si: 580 oC
  • Phosphorus doped a-Si: 580 oC
  • Boron doped polySi: 620 oC
  • Phosphorus doped polySi: 620 oC
  • Standard polySi: 620 oC
  • Amorphous polySi: 560-580 oC
  • Boron doped polySi: 600-620 oC

The process temperature vary over the furnace tube

Process pressure
  • 200-250 mTorr
  • 150-220 mTorr

The process pressure depends on the process

Gas flows
  • SiH4: 80 sccm
  • B2H6: 7 sccm
  • PH3: 7 sccm
  • SiH4: 50-70 sccm
  • BCl3: 1 sccm

The silane (SiH4) flow depends on the process

Substrates Batch size
  • 1-30 100 mm wafers

Including a testwafer with ~110 nm oxide

  • 1-25 or 1-50 100 mm wafers
  • 1-25 or 1-50 150 mm wafers

Including a testwafer with ~110 nm oxide

Substrate materials allowed
  • Silicon wafers (new or RCA cleaned)
    • with layers of silicon oxide or silicon (oxy)nitride
    • from the A, B and E stack furnaces
  • Quartz/fused silica wafers (RCA cleaned)
  • Silicon wafers (new or RCA cleaned)
    • with layers of silicon oxide or silicon (oxy)nitride
    • from the A, B and E stack furnaces
  • Quartz/fused silica wafers (RCA cleaned)


Rules for storage and RCA cleaning of wafers to the B4 and E2 furnaces

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