The T-ESC® Technology by ProTec® offers safe and easy handling as well as processing of fragile, thin and ultra-thin substrates (thinner 50 µm), e.g. GaAs, InP, LN, LT, thin silicon, thin MEMS wafer and many more. The basic concept behind this adhesive free temporary bonding technology involves using electrostatic force to chuck thin and ultra-thin wafers onto mobile rigid Carriers (T-ESC®). Such wafer-Carrier packages can be handled and processed like wafers of standard thickness.

Therefore, existing standard cassettes, handling tools, and fabrication equipment can be used without modifications. Additional effect: the warping and bowing of thin and ultra-thin substrates are eliminated, which is highly welcome. All our Carriers are available in standard sizes from 2" to 12" and additionally in customized shapes suited to the intended application.


Litho HT T-ESC®

The Lithography High-Temperature Transfer ElectroStatic Carrier (Litho HT T-ESC®) is our specifically designed solution for thin wafer handling support during whole lithography processes containing the different steps. It is based on our HT T-ESC®, due to a special design liquid between T-ESC® and wafer is avoided which enables lithography processing with high yields.

There is also an adapted version available for the so called slide off de-bonding process mainly used for compound semiconductors such as GaAs, InP, etc.

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Litho HT T-ESC®

Typical Applications

  • Solution for thin wafer handling support during lithography processes

  • HighTemperature (up to 400°C) and vacuum suited

  • Compatibility with existing handling systems (transport cassettes, vacuum, Bernoulli or mechanical end effectors, etc.)

  • Ultra Low contamination

  • High flatness

  • Outgassing free

  • Reusable

  • Sizes from 2" to 12", customized shapes and features possible

Recommended Processes

  • Spin Coating

  • EBR

  • Baking (Soft & Hardbake)

  • Exposure

  • Developing

  • Resist Stripping

  • Single Wafer Spin Etching

  • Slide Off De-Bonding

  • Handling


Lithography HT T-ESC Technology

(Single Wafer) Spin Etching

Spin Etching is following the same principle like spin coating. The substrate is clamped to a chuck and during spinning etching chemicals are jetted to the surface.


During Wafer processing the wafer needs to be transferred back and forth from cassettes to tools and also inside the tools from on station to the other. For fragile substrates this is already challenging, because they tend do brake or get cracks, which can lead to future breakage.  Also bowing of thinned substrates brings a lot of trouble for all tooling because they are usually not designed for this very special operation. Temporary bonding with our T-ESC® is a great help here as the processing tools only see a standard wafer and trouble with handling, therefore wafer breakage is eliminated.


Lithography is the general naming of the complete lithography processing steps such as coating, bake, exposure etc.

Spin Coating

Part of the Lithography processing, while the substrate is clamped on a chuck liquid chemicals are sprayed or jetted on to its surface. The substrate is rotating during this procedure or after it, so that the chemicals are spread uniform across the surface.


During Spin Coating a non uniform edge builds up at the wafer edge. This edge may cause problems during further processing and needs therefore to be removed which is called Edge Bead Removal.


During Lithography processing several baking steps are required to achieve the optimal grade of the resist to withstand the following substrate etching processes and to achieve the targeted structure in the end. Baking means basically the substrate together with the coating is heated to a specific temperature, this is kept for a while and afterwards the substrate is cooled down and ready for the next step.


The already coated wafer is irradiated by light or other irradiation sources through a mask, thus structures can be formed later out of this pattern.

Resist Developing

To generate a real structure out of the exposed coating, the coating is partially removed by a developing agent. This can be done either in a bath or again by a spinning type of tool. For our mobile electrostatic carriers we recommend to use spinning tools only. After the development stage the pattern in visible at the coating and the substrate can get structured in the patterned region after the baking procedure.

Resist Stripping

Not needed or unwanted photoresist is removed in the resist stripping process. This is usually done by chemicals. Also dry stripping process is possible, please refer to plasma clean/ashing.

Slide-Off De-Bonding

Slide-Off De-Bonding is used when a fragile wafer is glued to a temporary carrier and needs to be released with the Slide-Off De-Bonding after the processing. The glued carrier combined with the substrate is heated until the glue gets liquid, then the wafer or the carrier slides in one direction whereas the other is fixed in position. Afterwards the glue residues on the wafer have to be removed by chemicals. The whole process can be supported by our mobile electrostatic carrier (T-ESC®) and the thin wafer has always a rigid support during Slide-Off and the later cleaning step.

Our Machines

Maschine Protec ACU 3000

ACU 3000

A fully automated electrostatic chucking/de-chucking unit with up to 120 wafers and/or T-ESC® packages per hour, guarantying an highest yield during handling and many diagnostics features.

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MCU 3000 freigestellt

MCU 3000

A manual chucking / de-chucking unit of thin and ultra-thin substrates on carriers T-ESC® for flexible sizes from 4”/6” to 8”/12” with a high flexible mobile handling tool and diagnostic features.

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