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

Strip Comparison Table

	Plasma Asher 3: Descum	Plasma Asher 4 (Clean)	Plasma Asher 5 (Dirty)	Resist strip	Lift-off
Purpose	Resist descum	Resist stripping Resist descum	Resist stripping Resist descum	Resist stripping	Metal lift-off
Method	Plasma ashing	Plasma ashing	Plasma ashing	Solvent & ultrasonication	Solvent & ultrasonication
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)	NA	NA
Process power	10-100 W (10-100%)	150-1000 W	150-1000 W	NA	NA
Process solvent	NA	NA	NA	NMP (Remover 1165) IPA (rinsing agent)	NMP (Remover 1165) IPA (rinsing agent)
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	100 mm wafer: 1-25 150 mm wafer: 1-25	100 mm wafer: 1-25 150 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)	No metals No metal oxides Silicon substrates III-V substrates Glass substrates Polymer substrates Films, or patterned films, of resists/polymers	Silicon substrates III-V substrates (only if clean) Glass substrates Films, or patterned films, of any material except type IV (Pb, Te)

Plasma Ashing process parameters

	Resist stripping (PA4 & PA5)	Descum (PA3)	Descum (PA4 & PA5)	Surface treatment	Other ashing of organic material
Process pressure	1.3 mbar	0.8 mbar	1.3 mbar	0.5-1.5 mbar	0.5-1.5 mbar
Process gasses	O₂ (100 sccm) N₂ (100 sccm)	O₂ (45 sccm)	O₂ (100 sccm) N₂ (100 sccm)	O₂ N₂ CF₄	O₂
Process power	1000 W	100 W	200 W	150-1000 W	150-1000 W
Process time	20-90 minutes	1-10 minutes	5-15 minutes	Seconds to minutes	Many hours, material dependent
Substrate batch	1-25	1-2	1-25	1	1

Plasma Asher 3: Descum

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

The Plasma Asher 3: Descum is dedicated for resist descum, i.e. removal of remains resist traces after development. It has a small chamber, so you can only load a single 100 mm substrate, or a few smaller pieces.

In this machine, only Oxygen is used for processing.

Typical process parameters:
Process: Photoresist descumming
Pressure: 0.2-0.8 mbar
Gas: 45 sccm O₂
Power: 100 W (100%)
Time: 1 -10 minutes (depending on photoresist type and thickness)

Other materials have not been tested.

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

Process Information

Detailed information about descum processing on Plasma asher 3: Descum can be found here.

Plasma Asher 4

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

The Plasma Asher 4 can be used for the following processes:

Photoresist stripping
Descumming
Surface cleaning
Removal of organic passivation layers and masks

Plasma asher 4 has the following material restrictions:

No metals allowed
No metal oxides allowed
No III-V materials allowed

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

Typical stripping 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: 1000 W
Time (single wafer): 20-30 minutes
Time (full boat): 90 minutes

Process development notes

Information about process development for plasma asher 04 and plasma asher 05 can be found here.

Plasma Asher 5

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

The Plasma Asher 5 can be used for the following processes:

Photoresist stripping
Descumming
Surface cleaning
Removal of organic passivation layers and masks

Furthermore plasma processing using CF₄ in plasma asher 5 can be used for:

Etching of glass and ceramic
Etching of SiO₂, Si₃N₄, Si
Removal of polyimide layers

Plasma asher 5 can be used for almost every material, but if you have any doubt if your materials are compatible/allowed in plasma asher 5, feel free to ask the lithography group at Nanolab.

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

Process Information

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

Processes specifically only for plasma asher 5:

Resist Strip

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
Process	Wet resist strip	Metal lift-off process
Chemical	Remover 1165 (NMP)	Remover 1165 (NMP)
Process temperature	Up to 65°C	Up to 65°C
Substrate batch	1-25 wafers	1-25 wafers
Substrate size	100 mm wafers 150 mm wafers	100 mm wafers 150 mm wafers
Materials allowed	Silicon Silicon oxide Silicon nitride Silicon oxynitride	All metals except Type IV (Pb, Te)

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.