Specific Process Knowledge/Lithography/Strip

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Strip Comparison Table

Equipment Plasma asher 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!

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!

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


A typical process time for stripping of 1.5 µm AZ5214e resist is 15-25 min and for stripping of 9.5 µm AZ4562 resist is 20-35 min with the process parameters: 210 ml O/min or mixture of 210 ml O/min and 70 ml N/min, power 1000 W.

A Descum process in manual mode: O2: 70 sccm, N2: 70 sccm, power: 150 W, time: 10 min. Be sure to wait for cooling if the machine has been used at 1000W right before. At a load at 2 Fused silica wafers resist removed 0.01-01,5 um

Plasma asher 1

The Plasma Asher 1 is placed in C-1

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The Plasma Asher 1 (TePla 300 auto load model) can be used for the following process:

  • Photoresist stripping
  • Descumming
  • Surface cleaning after storage
  • Surface cleaning after processes using oil pump or diffusion pump vacuum
  • Surface cleaning as part of photolithography after wet developing of lacquer structures prior to wet or plasma etching
  • Stripping of photoresist layers after etching, including after being exposed to high temperatures as after implantation, ion etching, sputter etching, RIE
  • Removal of organic passivation layers and masks
  • Etching of glass and ceramic
  • Etching of SiO, SiN, Si
  • Removal of polyimide layers

The machine can be used for almost every materials, but if you have any doubt about your materials are compatible with the plasma process it is better to ask photolithography group at Nanolab.

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

Process Information

Plasma Asher 2

Plasma asher for removing AZ resist on 6" wafers: positioned in E-5

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The Plasma Asher 2 is the same as Plasma Asher 1 but has another loading system which is more convenient for batch loading of 6inch substrates.

In this machine, only O2 and N2 gases are used for processes (in PlasmaAsher1, CF4 is used as well).

The typical process parameters when operating the equipment:

  • Photeresist stripping

Pressure: 0.8 - 1.0 mbar

Gas: O2

Power: 600 - 1000 watts

Time: 5 -30 min., depending on photoresist type and thickness

A typical process time for stripping of 1.5 um AZ5214e resist is 25 min for 6 wafers load in a boat, recipe 18.

A Descum process in manual mode: O2:70, N2:70, power:150W, time:10 min

Be sure to wait for cooling if the mashine has been used at 1000W right before. At a load at 2 Fused silica wafers resist removed 0.01-01,5um

The other materials have not been tested yet.

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

Process Information


Plasma Asher 3: Descum

Plasma Asher 3: Descum is placed A-5

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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

Process Information



Resist Strip

Acetone strip bench in D-3

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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


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 60 oC Up to 60 oC
Batch size

1-25 wafers at a time

1-25 wafer at a time

Size of substrate

4" wafers 6" wafers

4" wafers 6" wafers

Allowed materials
  • Silicon
  • Silicon Oxide
  • Silicon Nitride
  • Silicon Oxynitride
  • All metals except Type IV (Pb, Te)