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__TOC__
__TOC__


=Plasma Asher 1=
= Descum Comparison Table =
<span style="color:red">Plasma asher 1 was decommissioned 2024-12-02.</span>
 
[[Specific Process Knowledge/Lithography/Descum/PlasmaAsher1|Information about decommissioned tool can be found here.]]
 
=Plasma Asher 2=
<span style="color:red">Plasma asher 2 was decommissioned 2024-12-02.</span>
 
[[Specific Process Knowledge/Lithography/Descum/PlasmaAsher2|Information about decommissioned tool can be found here.]]
 
=Plasma Asher 3: Descum=
The user manual(s), quality control procedure(s) and results and contact information can be found in [http://labmanager.dtu.dk/function.php?module=Machine&view=view&mach=423 LabManager] - '''requires login'''
 
Plasma Asher 3 is specifically used for controlled descum process after lithography. Please note that you only can process a single 100 mm wafer, or one small sample, at a time.
The plasma asher is equipped with 2 gaslines: oxygen and nitrogen, but all standard processes use only oxygen (as recommended by Diener).
 
 
'''Ashing of  AZ MiR701 resist:'''<br>
You can use two different descum process developments: you can either change power settings or processing chamber pressure.
 
 
'''Testing different power settings:'''
[[image:AZMIR701_power_settings.png|640px|thumb|Descum results for different power settings]]
 
'''Recipe settings:'''
*O2 flow: 5 sccm
*N2 flow: 0
*Pressure: 0.2 mbar
*Power: Varied
 
 
'''Experiment parameters:'''
{| {{table}}
| align="center" |
{|border="1" cellspacing="1" cellpadding="10" style="text-align:left;"
|- style="background:LightGrey"
| ||FW/REV|| C2/C1 || Power
|-
|'''recipe 1''' || 50/0 || 52/31 || 50%
|-
|'''recipe 2''' || 100/0 || 53/31 || 100%
|-
|'''recipe 3''' || 20/0 || 51/34 || 20%
|-
|}
|}
<br clear="all" />
 
 
'''Testing different pressure settings:'''
[[image:AZMIR701_pressure_settings.png|640px|thumb|Descum results for different pressure settings]]
 
'''Recipe settings:'''
*O2 flow: varied
*N2 flow: 0
*Pressure: varied
*Power: V100% (100 W)
 
 
'''Experiment parameters:'''
{| {{table}}
| align="center" |
{|border="1" cellspacing="1" cellpadding="10" style="text-align:left;"
|- style="background:LightGrey"
| ||FW/REV|| C2/C1 || Oxygen || Pressure
|-
|'''recipe 1'''|| 100/0 || 53/31 || 5 || 0,2
|-
|'''recipe 2''' || 100/0 || 37/38 || 45 || 0,8
|-
|}
|}
<br clear="all" />
 
'''Ashing of AZ5214E resist:'''
[[image:AZ5214E_pressure_settings.png|640px|thumb|Descum results for different pressure settings]]
 
 
'''Recipe settings:'''
*O2 flow: varied
*N2 flow: 0
*Pressure: varied
*Power: V100% (100 W)
 
 
'''Experiment parameters:'''
{| {{table}}
| align="center" |
{|border="1" cellspacing="1" cellpadding="10" style="text-align:left;"
|- style="background:LightGrey"
| ||FW/REV|| C2/C1 || Oxygen || Pressure
|-
|'''recipe 1'''|| 100/0 || 53/31 || 17 || 0,4
|-
|'''recipe 2''' || 100/0 || 37/39 || 45 || 0,8
|-
|}
|}
<br clear="all" />
 
=Plasma Asher 4=
==Descum processing in plasma asher 4 & 5==
Descum of AZ 5214E on 100 mm wafers. The descum process was tested for single substrates, as well as 3 substrates, placed vertically in the glass boat. For the 3 substrates only the center substrate was used for testing, the front and back wafers were used as dummy wafers.<br>
 
When running multiple wafers, the first and last wafers should always be dummy wafers.
 
The user manual, risk assessment, and contact information can be found in [http://labmanager.dtu.dk/function.php?module=Machine&view=view&mach=530 LabManager] - '''requires login'''
 
'''Typical descum parameters'''
*O<sub>2</sub>: 100 sccm
*N<sub>2</sub>: 100 sccm
*Pressure (DSC): 1.3 mbar
*Power: 200 W
*Chamber temperature at start: 30°C
*Time (single wafer): 5-10 minutes = 35-72 nm ashed
*Time (multiple wafers): 10-15 minutes = 40-80 nm ashed
 
{| class="wikitable"
{| class="wikitable"
|-
|-
! Test setup !! Single substrate !! Center of 3 substrates
!
|-
! [[Specific_Process_Knowledge/Lithography/Descum#Plasma Asher 3: Descum|Plasma Asher 3: Descum]]
! scope=row| Test results
! [[Specific_Process_Knowledge/Lithography/Descum#Plasma_Asher 4|Plasma Asher 4 (Clean)]]
| Ashing rate: 5.7 ±2.1 nm/min<br>Non-uniformity: 0.6 ±0.4% || Ashing rate: 3.8 ±1.6 nm/min<br>Non-uniformity: 0.4 ±0.2%
! [[Specific_Process_Knowledge/Lithography/Descum#Plasma Asher 5|Plasma Asher 5 (Dirty)]]
|-
|-
! scope=row| Wafers
! scope=row style="text-align: left;" | Purpose
| 1 || 3
| Resist descum
|
*Resist stripping
*Resist descum
|
*Resist stripping
*Resist descum
|-
|-
! scope=row| Wafer size
! scope=row style="text-align: left;" | Method
| 100 mm || 100 mm
| Plasma ashing
| Plasma ashing
| Plasma ashing
|-
|-
! scope=row| Boat position
! scope=row style="text-align: left;" | Process gasses
| Center of chamber || Center of chamber
| O<sub>2</sub> (50 sccm)
|
*O<sub>2</sub> (0-500 sccm)
*N<sub>2</sub> (0-500 sccm)
|
*O<sub>2</sub> (0-500 sccm)
*N<sub>2</sub> (0-500 sccm)
*CF<sub>4</sub> (0-200 sccm)
|-
|-
! scope=row| Test wafer position
! scope=row style="text-align: left;" | Process power
| Center of boat || Center of boat
| 10-100 W (10-100%)
| 150-1000 W
| 150-1000 W
|-
|-
! scope=row| Total gas flow rate
! scope=row style="text-align: left;" | Substrate batch
| 200 sccm || 200 sccm
|
*Chips: several
*50 mm wafer: several
*100 mm wafer: 1
|
*Chips: several
*50 mm wafer: several
*100 mm wafer: 1-25
*150 mm wafer: 1-25
*200 mm wafer: 1-25
|
*Chips: several
*50 mm wafer: several
*100 mm wafer: 1-25
*150 mm wafer: 1-25
*200 mm wafer: 1-25
|-
|-
! scope=row| Gas mix ratio
! scope=row style="text-align: left;" | Substrate materials
| 50% N<sub>2</sub> || 50% N<sub>2</sub>
|
|-
*<span style="color:red">'''No polymer substrates'''</span><br>
! scope=row| Chamber pressure
*Silicon substrates
| 1.3 mbar || 1.3 mbar
*III-V substrates
|-
*Glass substrates
! scope=row| Power
*Films, or patterned films, of any material except type IV (Pb, Te)
| 200 W || 200 W
|
|-
*<span style="color:red">'''No metals'''</span><br>
! scope=row| Test processing time
*<span style="color:red">'''No metal oxides'''</span><br>
| Tested parameter || Tested parameter
*<span style="color:red">'''No III-V materials'''</span><br>
|-
*Silicon substrates
! scope=row| Test average temperature
*Glass substrates
| 33°C || 33°C
*Polymer substrates
*Films, or patterned films, of resists/polymers
|
*Silicon substrates
*III-V substrates
*Glass substrates
*Polymer substrates
*Films, or patterned films, of any material except type IV (Pb, Te)
|}
|}
<br clear="all" />
<br clear="all" />
<hr>


{{:Specific Process Knowledge/Lithography/Descum/plasmaAsher03}}


[[File:PA_descum_single_v3.png|400px|thumb|Ashing amount and ashing rate when processing a single 100 mm wafer.|right]]
{{:Specific Process Knowledge/Lithography/Descum/plasmaAsher04}}
'''Single wafer ashing rate'''<br>
{| class="wikitable"
|-
! Ashing time [min]: !! 1 !! 2 !! 5 !! 10 !! 15
|-
| Ashing amount [nm]: || 5.2 || 6.2 || 35.1 || 72.3 || 87.1
|-
| Ashing rate [nm/min]: || 5.2 || 3.1 || 7.0 || 7.2 || 5.8
|}


{{:Specific Process Knowledge/Lithography/Descum/plasmaAsher05}}


'''Single wafer non-uniformity'''<br>
=Decommisioned tools=
{| class="wikitable"
<span style="color:red">Plasma asher 1 was decommissioned 2024-12-02.</span>
|-
! Ashing time [min]: !! 1 !! 2 !! 5 !! 10 !! 15
|-
| Film thickness range, before descum [nm]: || 11 || 12 || 10 || 11 || 9
|-
| Pre-ashing non-uniformity [%]: || 0.37 || 0.40 || 0.33 || 0.37 || 0.30
|-
| Film thickness range, after descum [nm]: || 10 || 10 || 12 || 19 || 33
|-
| Post-ashing non-uniformity [%]: || 0.33 || 0.33 || 0.41 || 0.66 || 1.18
|}


<br clear="all" />
[[Specific Process Knowledge/Lithography/Descum/PlasmaAsher1|Information about decommissioned tool can be found here.]]
<hr>




[[File:PA_descum_multi_v3.png|400px|thumb|Ashing amount and ashing rate when processing multiple 100 mm wafers. Test measured on the center of 3 wafers.|right]]
<span style="color:red">Plasma asher 2 was decommissioned 2024-12-02.</span>
'''Multi wafer ashing rate'''<br>
{| class="wikitable"
|-
! Ashing time [min]: !! 1 !! 2 !! 5 !! 10 !! 15
|-
| Ashing amount [nm]: || 4.3 || 6.7 || 10.1 || 39.5 || 78.8
|-
| Ashing rate [nm/min]: || 4.3 || 3.4 || 2.0 || 4.0 || 5.3
|}
 
 
'''Multi wafer non-uniformity'''<br>
{| class="wikitable"
|-
! Ashing time [min]: !! 1 !! 2 !! 5 !! 10 !! 15
|-
| Film thickness range, before descum [nm]: || 11 || 13 || 11 || 12 || 14
|-
| Pre-ashing non-uniformity [%]: || 0.37 || 0.43 || 0.37 || 0.40 || 0.46
|-
| Film thickness range, after descum [nm]: || 11 || 9 || 10 || 12 || 21
|-
| Post-ashing non-uniformity [%]: || 0.37 || 0.30 || 0.33 || 0.41 || 0.74
|}


[[Specific Process Knowledge/Lithography/Descum/PlasmaAsher2|Information about decommissioned tool can be found here.]]
<br clear="all" />
<br clear="all" />
<hr>
'''Comparison between single substrate processing and multi substrate processing'''<br>
Processing a single substrate using the standard descum settings will provide users with a relatively controllable and uniform process. Adding dummy substrates in close proximity with the process substrate will reduce the ashing rate and improve the uniformity:
<gallery mode="packed-hover" heights="150">
PA_descum_compareAmount_v1.png|Ashing amount
PA_descum_compareRate_v1.png|Ashing rate
PA_descum_compareUniformity_v1.png|Non-uniformity
</gallery>
<br clear="all" />
=Plasma Asher 5=
Plasma asher 5 is identical to plasma asher 4, see descum processing for plasma asher 4 [[Specific_Process_Knowledge/Lithography/Descum#Descum_processing_in_plasma_asher_4_&_5|here]].

Latest revision as of 12:31, 13 January 2026

The content on this page, including all images and pictures, was created by DTU Nanolab staff, unless otherwise stated.

Feedback to this page: click here

Descum Comparison Table

Plasma Asher 3: Descum Plasma Asher 4 (Clean) Plasma Asher 5 (Dirty)
Purpose Resist descum
  • Resist stripping
  • Resist descum
  • Resist stripping
  • Resist descum
Method Plasma ashing Plasma ashing Plasma ashing
Process gasses O2 (50 sccm)
  • O2 (0-500 sccm)
  • N2 (0-500 sccm)
  • O2 (0-500 sccm)
  • N2 (0-500 sccm)
  • CF4 (0-200 sccm)
Process power 10-100 W (10-100%) 150-1000 W 150-1000 W
Substrate batch
  • Chips: several
  • 50 mm wafer: several
  • 100 mm wafer: 1
  • Chips: several
  • 50 mm wafer: several
  • 100 mm wafer: 1-25
  • 150 mm wafer: 1-25
  • 200 mm wafer: 1-25
  • Chips: several
  • 50 mm wafer: several
  • 100 mm wafer: 1-25
  • 150 mm wafer: 1-25
  • 200 mm wafer: 1-25
Substrate materials
  • No polymer substrates
  • Silicon substrates
  • III-V substrates
  • Glass substrates
  • Films, or patterned films, of any material except type IV (Pb, Te)
  • No metals
  • No metal oxides
  • No III-V materials
  • Silicon substrates
  • Glass substrates
  • Polymer substrates
  • Films, or patterned films, of resists/polymers
  • Silicon substrates
  • III-V substrates
  • Glass substrates
  • Polymer substrates
  • Films, or patterned films, of any material except type IV (Pb, Te)


Plasma Asher 3: Descum

Product name: Diener Pico Plasma Asher
Year of purchase: 2014

The user manual(s), quality control procedure(s) and results and contact information can be found in LabManager - requires login

Plasma Asher 3 is specifically used for controlled descum process after lithography. Please note that you only can process a single 100 mm wafer, or one small sample, at a time. The plasma asher is equipped with 2 gaslines: oxygen and nitrogen, but all standard processes use only oxygen (as recommended by Diener).

Process parameters
You can manipulate two different descum process development parameters: you can either change power or chamber pressure.

Power testing - AZ MiR 701

Descum results for different power settings

Recipe settings:

  • Resist: AZ MiR 701
  • O2 flow: 5 sccm
  • N2 flow: 0
  • Pressure: 0.2 mbar
  • Power: Varied
Experiment parameters
Forward/reverse C2/C1 Power
recipe 1 50/0 52/31 50%
recipe 2 100/0 53/31 100%
recipe 3 20/0 51/34 20%

Pressure testing - AZ MiR 701

Descum results for different pressure settings

Recipe settings:

  • Resist: AZ MiR 701
  • O2 flow: varied
  • N2 flow: 0
  • Pressure: varied
  • Power: V100% (100 W)
Experiment parameters
Forward/reverse C2/C1 Oxygen Pressure
recipe 1 100/0 52/31 5 0.2
recipe 2 100/0 37/38 45 0.8

Pressure testing - AZ 5214E

Descum results for different pressure settings

Recipe settings:

  • Resist: AZ 5214E
  • O2 flow: varied
  • N2 flow: 0
  • Pressure: varied
  • Power: V100% (100 W)
Experiment parameters
Forward/reverse C2/C1 Oxygen Pressure
recipe 1 100/0 52/31 17 0.4
recipe 2 100/0 37/39 45 0.8


Plasma Asher 4

Product name: PVA Tepla Gigabatch 380M
Year of purchase: 2024

Descum of AZ 5214E on 100 mm wafers. The descum process development was done for a single substrate, as well as 3 substrates (for decreased ashing rate and improved ashing uniformity). The substrates were placed vertically in the glass boat.

  • Single vertical substrate
    Single vertical substrate
  • 3 vertical substrates: Dummy - Test - Dummy
    3 vertical substrates:
    Dummy - Test - Dummy

For the 3 substrates only the center substrate was used for testing, the front and back wafers were used as dummy wafers. The wafers were placed in consecutive slots - when running multiple wafers in this way, the first and last wafers should always be dummy wafers.

The user manual, risk assessment, and contact information can be found in LabManager - requires login

Typical descum parameters
Tested with 1.5 µm AZ 5214E on 100 mm silicon substrate.

  • O2: 100 sccm
  • N2: 100 sccm
  • Pressure (DSC): 1.3 mbar
  • Power: 200 W
  • Chamber temperature at start (with door closed): 30°C
  • Time (single wafer): 5-10 minutes = 35-72 nm ashed
  • Time (multiple wafers): 10-15 minutes = 40-80 nm ashed
Single substrate Center of 3 substrates
Test results: ashing rate 5.7 ±2.1 nm/min 3.8 ±1.6 nm/min
Test results: non-uniformity 0.6 ±0.4% 0.4 ±0.2%
Wafers 1 3
Wafer size 100 mm 100 mm
Boat position Center of chamber Center of chamber
Test wafer position Center of boat Center of boat
Total gas flow rate 200 sccm 200 sccm
Gas mix ratio 50% N2 50% N2
Chamber pressure 1.3 mbar 1.3 mbar
Power 200 W 200 W
Test processing time Tested parameter Tested parameter
Test average temperature 33°C 33°C


Single wafer descum ashing rate and uniformity for plasma asher 4 & 5

Ashing amount and ashing rate when processing a single 100 mm wafer.
Ashing amount and rate
Ashing time [min]: 1 2 5 10 15
Ashing amount [nm]: 5.2 6.2 35.1 72.3 87.1
Ashing rate [nm/min]: 5.2 3.1 7.0 7.2 5.8
Ashing non-uniformity
Ashing time [min]: 1 2 5 10 15
Pre-descum film thickness range [nm]: 11 12 10 11 9
Pre-descum non-uniformity [%]: 0.37 0.40 0.33 0.37 0.30
Post-descum film thickness range [nm]: 10 10 12 19 33
Post-descum non-uniformity [%]: 0.33 0.33 0.41 0.66 1.18


Multi wafer descum ashing rate and uniformity for plasma asher 4 & 5

Ashing amount and ashing rate when processing multiple 100 mm wafers. Test measured on the center of 3 wafers.
Ashing amount and rate
Ashing time [min]: 1 2 5 10 15
Ashing amount [nm]: 4.3 6.7 10.1 39.5 78.8
Ashing rate [nm/min]: 4.3 3.4 2.0 4.0 5.3
Ashing non-uniformity
Ashing time [min]: 1 2 5 10 15
Pre-descum film thickness range [nm]: 11 13 11 12 14
Pre-descum non-uniformity [%]: 0.37 0.43 0.37 0.40 0.46
Post-descum film thickness range [nm]: 11 9 10 12 21
Post-descum non-uniformity [%]: 0.37 0.30 0.33 0.41 0.74


Comparison between single substrate processing and multi substrate processing for plasma asher 4 & 5

Processing a single substrate using the standard descum settings will provide users with a relatively controllable and uniform process. Adding dummy substrates in close proximity with the process substrate will reduce the ashing rate and improve the uniformity:

  • Ashing amount
    Ashing amount
  • Ashing rate
    Ashing rate
  • Non-uniformity
    Non-uniformity


Comparison of ashing rate between substrate sizes

It is assumed that the low power descum rates, for different substrate sizes, follows the same pattern as the high power ashing rates, which can be seen here.

Plasma Asher 5

Product name: PVA Tepla Gigabatch 380M
Year of purchase: 2024

Plasma asher 5 is identical to plasma asher 4, see descum processing for plasma asher 4 here.

Decommisioned tools

Plasma asher 1 was decommissioned 2024-12-02.

Information about decommissioned tool can be found here.


Plasma asher 2 was decommissioned 2024-12-02.

Information about decommissioned tool can be found here.

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