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Specific Process Knowledge/Lithography/Strip

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Strip Comparison Table

Equipment Plasma Asher 1 Plasma Asher 2 Plasma Asher 3: Descum Resist strip Lift-off
Purpose

All purposes

Clean wafers only, no metal

Resist descum

Resist strip, no metal lift off

Lift-off

Method

Plasma ashing

Plasma ashing

Plasma ashing

Solvent and ultra sound

Solvent and ultra sound

Process parameters Process gasses
  • O2 (0 - 400 sccm)
  • N2
  • CF4
  • O2 (0 - 400 sccm)
  • N2
  • O2 (flow unknown)
  • NA
  • NA
Max. process power
  • 1000 W
  • 1000 W
  • 100% (power unknown)
  • NA
  • NA
Solvent
  • NA
  • NA
  • NA
  • NMP (Remover 1165)
  • Rinse in IPA
  • NMP (Remover 1165)
  • Rinse in IPA
Substrates Batch size
  • 1 small sample
  • 1 50 mm wafer
  • 1 - 30 100 mm wafers
  • 1 - 25 150 mm wafers
  • 1 small sample
  • 1 50 mm wafer
  • 1 - 30 100 mm wafers
  • 1 - 25 150 mm wafers
  • 1 small sample
  • 1 50 mm wafer
  • 1 100 mm wafer
  • 1 - 25 100 mm wafers
  • 1 - 25 150 mm wafers
  • 1 - 25 100 mm wafers
  • 1 - 25 150 mm wafers
Allowed materials
  • Silicon, glass, and polymer substrates
  • Film or pattern of all but Type IV

No metal allowed!

  • Silicon, glass, and polymer substrates
  • Film or pattern of photoresist/polymer
  • Silicon, III-V, and glass substrates
  • Film or pattern of all but Type IV

No metal allowed!

  • Silicon, glass, and polymer substrates
  • Film or pattern of photoresist/polymer
  • Silicon and glass substrates
  • Film or pattern of all but Type IV


Plasma Ashing

Photoresist stripping Descum after lithography Surface treatment of plastic, ceramic and metal Ashing of organic material
Process pressure 0.8- 1.2mbar 0.5- 1.0mbar 0.5- 1.0mbar 0.8-1.5mbar
Process gases
  • O2 (400 sccm)
  • N2 (0-70 sccm)
  • O2 (70-210 sccm)
  • N2 (0-70 sccm)
O2, CF4, N2 or their mixtures O2
Process power 600-1000W 150-300W 150-300W 1000W or less for heat- sensitive materials
Process time 5-60 minutes 1-5 minutes a few seconds to a few minutes Between 0.5 and 20 hours, depending on the material
Batch size 1-30 1-10 1 wafer at a time 1 wafer at a time, use a container, e.g Petri dish



Typical process time for stripping in plasma asher 1 or 2:

  • 1.5 µm AZ 5214E resist film: ~15 min
  • 10 µm AZ 4562 resist film: ~45 min

Typical process parameters:

  • O2: 400 ml/min
  • N2: 70 ml/min
  • Power: 1000 W


A typical descum process in plasma asher 1 or 2:

  • O2: 70 ml/min
  • N2: 70 ml/min
  • Power: 150 W
  • Time : 10 min


Be sure to wait for chamber to cool down to room temperature, before runinng descum processes in plasma asher 1 or 2. At a load of 2 Fused silica wafers, the amount of resist removed will be 10 - 1500 nm.

NB: Use dedicated descum asher Plasma Asher 3: Descum for descumming.

Plasma Asher 1

Plasma asher 1 was decommissioned 2024-12-02.

Information about decommissioned tool

Plasma Asher 2

Plasma asher 2 was decommissioned 2024-12-02.

Information about decommissioned tool

Plasma Asher 3: Descum

Plasma Asher 3: Descum is placed A-5

The Plasma Asher 3: Descum dedicated for resist descum i.e. removal of remains resist traces after development. It has a small chamber, so you can only load one 4 inch substrate ad time or few smaller pieces.

In this machine, only O2 and N2 gases are used for processes.

The typical process parameters when operating the equipment:

  • Photeresist descum

Pressure: 0.2 - 0.8mbar Gas: O2 Power: 50% - 100% Time: 1 -10 min., depending on photoresist type and thickness

The other materials have not been tested yet.

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

Process Information



Plasma Asher 4

Coming soon

Plasma Asher 5

Coming soon

Resist Strip

Resist strip bench in D-3

This resist strip is only for wafers without metal and SU-8.

There are one Remover 1165 bath for stripping and one IPA bath for rinsing.

Here are the main rules for resist strip use:

  • Place the wafers in a wafer holder and put them in the first bath for 10 min, this time is depending how much resist you have on the surface.
  • After the strip rinse your wafers in the IPA bath for 2-3 min.
  • Rinse your wafers for 4-5 min. in running water after stripping.


The user manual and contact information can be found in LabManager: Resist Strip - requires login


Overview of wet bench 06 and 07

Resist Strip Lift-off
General description Wet stripping of resist Lift-off process
Chemical solution NMP Remover 1165 NMP Remover 1165
Process temperature Up to 65°C Up to 65°C
Batch size

1 - 25 wafers

1 - 25 wafers

Size of substrate
  • 100 mm wafers
  • 150 mm wafers
  • 100 mm wafers
  • 150 mm wafers
Allowed materials
  • Silicon
  • Silicon Oxide
  • Silicon Nitride
  • Silicon Oxynitride

All metals except Type IV (Pb, Te)