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

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==LPCVD (Low Pressure Chemical Vapor Deposition) PolySilicon==
'''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]'''
[[Image:A4_Furnace_PolySi.jpg|300x300px|thumb|A4 Furnace PolySilicon (situated in cleanroom 2]]


Danchip has two furnaces for deposition of LPCVD polysilicon: A new 6" furnace (installed in 2011) for deposition of standard polySi, amorphous polySi and boron doped polySi on 4" or 6" wafers and an older 4" furnace (installed in 1995) for deposition of standard polySi, amorphous polySi, boron- and phosphorous doped polySi on 4" wafers. In LabManager the two furnaces are named "Furnace: LPCVD Poly-Si" and "Furnace: LPCVD Poly-Silicon 6inch", respectively. Both furnaces are Tempress horizontal furnaces.
<i> Unless otherwise stated, this page is written by <b>DTU Nanolab internal</b></i>


The LPCVD polysilicon deposition is a batch process, where polySi is deposited on a batch of 25 or 50 wafers (6" polySi furnace) or 30 wafers (4" polySi furnace). The polySi has a good step coverage, and especially for standard polySi the film thickness is very uniform over the wafers.
[[Category: Equipment|Thin film LPCVD Poly]]
[[Category: Furnaces|LPCVD Poly]]
[[Category: Thin Film Deposition|LPCVD Poly]]


The reactive gas is silane (SiH<sub>4</sub>). The dopant for boron doped polySi is BCl<sub>3</sub> (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>. For standard polysilion the deposition takes place at a temperature of 620<sup>o</sup>C and a pressure of 200-250 MTorr. For amorphous polysilicon the deposition temperatures and thus the deposition rate are lower, and for boron and phosphorous doped polySi the deposition temperature is 600<sup>o</sup>C - 620<sup>o</sup>C depending on whether you use the 6" or the 4" polySi furnace. For phousphorous doped polySi the deposition rate is approximately ten times lower than for boron doped polySi. More process information about the process parameters can be found in the table below.


To get information on how to operate the furnaces please read the user manuals which are uploaded to the machine pages in LabManager or consult the Furnace group at Danchip (furnace@danchip.dtu.dk).
==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]]


==Process Knowledge==
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.
Please take a look at the process side for deposition of Silicon Nitride using LPCVD:
 
[[Specific Process Knowledge/Thin film deposition/Deposition of polysilicon/Deposition of polysilicon using LPCVD|Deposition of polysilicon using LPCVD]]
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.
<br clear="all" />
 
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==
==Overview of the performance of the LPCVD polysilicon processes and some process related parameters==


{| border="2" cellspacing="0" cellpadding="10"  
{| 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 LPCVD polysilicon
|style="background:LightGrey; color:black"|Deposition of  
|style="background:WhiteSmoke; color:black"|
|style="background:WhiteSmoke; color:black"|
6" furnace:
*Standard polySi
*Standard polySi
*Amorphous polySi
*Amorphous polySi
*Boron doped polySi (BCl<math>_3</math> dopant)
*Boron doped polySi (B<sub>2</sub>H<sub>6</sub> dopant)
4" furnace:
*Phosphorus doped polySi (PH<sub>3</sub> dopant)
|style="background:WhiteSmoke; color:black"|
*Standard polySi
*Standard polySi
*Amorphous polySi
*Amorphous polySi
*Boron doped polySi (B<math>_2</math>H<math>_6</math> dopant)
*Boron doped polySi (BCl<sub>3</sub> dopant)
*Phosphorus doped polySi
|-
|-
!style="background:silver; color:black" align="left" valign="top" rowspan="3"|Performance
!style="background:silver; color:black" align="center" valign="center" rowspan="2"|Performance
|style="background:LightGrey; color:black"|Film thickness
|style="background:LightGrey; color:black"|Step coverage
|style="background:WhiteSmoke; color:black"|
|style="background:WhiteSmoke; color:black"|
6" furnace:
*Very Good
*Standard polySi: 0-2000 nm
*Amorphous polySi: 0-1000 nm
*Boron doped polySi: 0-1000 nm
4" furnace:
*Standard polySi: 0-2000 nm
*Amorphous polySi: 0-2000 nm
*Boron doped polySi: 0-2000 nm
*Phosphorus doped polySi: 0-1000 nm
Thicker layers have to be deposited over more runs
|-
|style="background:LightGrey; color:black"|Step coverage
|style="background:WhiteSmoke; color:black"|
|style="background:WhiteSmoke; color:black"|
*Good
*Very good
|-
|-
|style="background:LightGrey; color:black"|Film quality
|style="background:LightGrey; color:black"|Film quality
|style="background:WhiteSmoke; color:black"|
*Deposition on both sides of the substrate
*Good uniformity over the wafer
|style="background:WhiteSmoke; color:black"|
|style="background:WhiteSmoke; color:black"|
*Deposition on both sides of the substrate
*Deposition on both sides of the substrate
*Good uniformity over the wafer
*Good uniformity over the wafer
|-
|-
!style="background:silver; color:black" align="left" valign="top" rowspan="3"|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"|
6" furnace:
*Standard polySi: 620 <sup>o</sup>C
*Standard polySi: 620 <sup>o</sup>C
*Amorphous polySi: 560-580 <sup>o</sup>C
*Amorphous polySi: 560-580 <sup>o</sup>C
*Boron doped polySi: 600-620 <sup>o</sup>C
*Boron doped a-Si: 580 <sup>o</sup>C
4" furnace:
*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
*Standard polySi: 620 <sup>o</sup>C
*Amorphous polySi: 560-580 <sup>o</sup>C
*Amorphous polySi: 560-580 <sup>o</sup>C
*Boron doped polySi: 620 <sup>o</sup>C
*Boron doped polySi: 600-620 <sup>o</sup>C
*Phosphorus doped polySi: 620 <sup>o</sup>C
 
The process temperature vary over the furnace tube
The process temperature vary over the furnace tube
|-
|-
|style="background:LightGrey; color:black"|Process pressure
|style="background:LightGrey; color:black"|Process pressure
|style="background:WhiteSmoke; color:black"|
|style="background:WhiteSmoke; color:black"|
6" furnace:
*200-250 mTorr
|style="background:WhiteSmoke; color:black"|
*150-220 mTorr
*150-220 mTorr
4" furnace:
The process pressure depends on the process
*250 mTorr
The process pressure depends on the actual process
|-
|-
|style="background:LightGrey; color:black"|Gas flows
|style="background:LightGrey; color:black"|Gas flows
|style="background:WhiteSmoke; color:black"|
|style="background:WhiteSmoke; color:black"|
6" furnace:
*SiH<sub>4</sub>: 80 sccm
*SiH<math>_4</math>: 50-70 sccm
*B<sub>2</sub>H<sub>6</sub>: 7 sccm
*BCl<math>_1</math>: 1 sccm
*PH<sub>3</sub>: 7 sccm
4" furnace:
|style="background:WhiteSmoke; color:black"|
*SiH<math>_4</math>: 80 sccm
*SiH<sub>4</sub>: 50-70 sccm
*B<math>_2</math>H<math>_6</math>: 7 sccm
*BCl<sub>3</sub>: 1 sccm
*PH<math>_1</math>: 7 sccm
The silane (SiH<sub>4</sub>) flow depends on the process
The silane (SiH<math>_4</math>) flow depends on the actual process
|-
|-
!style="background:silver; color:black" align="left" valign="top" rowspan="2"|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"|
6" furnace:
*1-30 100 mm wafers
*1-25 4" wafers or 6" wafers per run
Including a testwafer with ~110 nm oxide
4" furnace:
|style="background:WhiteSmoke; color:black"|
*1-30 4" wafers per run
*1-25 or 1-50 100 mm wafers
Deposition on both sides of the substrate
*1-25 or 1-50 150 mm wafers
Including a testwafer with ~110 nm oxide
|style="background:WhiteSmoke; color:black"|
|-
|-
| style="background:LightGrey; color:black"|Substrate materials allowed
| style="background:LightGrey; color:black"|Substrate materials allowed
|style="background:WhiteSmoke; color:black"|
|style="background:WhiteSmoke; color:black"|
*Silicon wafers (only clean wafers):
*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  
**from furnaces in stack A or B in cleanroom 2
**from the A, B and E stack furnaces
*Quartz wafers (RCA cleaned)
*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

Feedback to this page: click here

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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