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Specific Process Knowledge/Lithography/Descum

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Plasma Asher 1

Plasma asher 1 was decommissioned 2024-12-02.

Information about decommissioned tool

Plasma Asher 2

Jitka Urbánková & Jesper Hanberg, December 2019

Descum results plasma asher 2 - recipe 1

This tool has been decomissioned 2024-12-02.

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

Descum of AZ Mir 701 resist on 100mm silicon wafer. Five wafers were placed vertically in chamber.


recipe 1:

  • O2 flow: 100 ml/min
  • N2 flow: 100 ml/min
  • Power: 150 W
Ashing time (min) 1 2 3 4 6 7 8 9 10 12 14 15 20
Etched Thickness (nm) 8,7 5,1 12,5 6,2 31,8 86,0 25,7 46,8 38,3 49,7 59,4 140,1 360,7
Initial temperature (°C) 28 21 31 21 22 28 25 24 21 24 24 22 22
Descum results plasma asher 2 - recipe 2


recipe 2:

  • O2 flow: 500 ml/min
  • N2 flow: 0 ml/min
  • Power: 200 W
Ashing time (min) 1 2 3 4 5 6 7 8 10 12 15 20
Etched Thickness (nm) 8,1 9,4 16,8 55,2 44,0 47,5 42,5 55,1 85,3 122,4 184,8 305,9
Initial temperature (°C) 22 21 21 22 22 22 21 21 20 21 21 22

A linear time dependence was observed after etching 7 minutes or more (recipe 2).

Plasma Asher 3: Descum

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).


Ashing of AZ MiR701 resist:
You can use two different descum process developments: you can either change power settings or processing chamber pressure.


Testing different power settings:

Descum results for different power settings

Recipe settings:

  • O2 flow: 5 sccm
  • N2 flow: 0
  • Pressure: 0.2 mbar
  • Power: Varied


Experiment parameters:

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%



Testing different pressure settings:

Descum results for different pressure settings

Recipe settings:

  • O2 flow: varied
  • N2 flow: 0
  • Pressure: varied
  • Power: V100% (100 W)


Experiment parameters:

FW/REV C2/C1 Oxygen Pressure
recipe 1 100/0 53/31 5 0,2
recipe 2 100/0 37/38 45 0,8


Ashing of AZ5214E resist:

Descum results for different pressure settings


Recipe settings:

  • O2 flow: varied
  • N2 flow: 0
  • Pressure: varied
  • Power: V100% (100 W)


Experiment parameters:

FW/REV C2/C1 Oxygen Pressure
recipe 1 100/0 53/31 17 0,4
recipe 2 100/0 37/39 45 0,8