A multi-stage production process is necessary before our customers' circuit layout becomes the "photomask" tool for the semiconductor factories. This does not begin with physical processing, but with complex processing of the data in a high-performance computer cluster.
In this process, the circuit layout is converted into an image that is transferred to a photoactive lacquer layer by means of exposure to electrons or photons. The equipment used for this process is an electron or laser light-based writer. This writing process is the heart of the manufacturing process and defines structures that are up to a thousand times smaller than the diameter of a hair. The photomasks themselves are high-purity quartz plates with a special layer structure that differs depending on the desired application. In the simplest case, this consists of an absorber layer and the above-mentioned photoactive layer. After the writing process, the photoactive layer is developed and the resulting structures are transferred to the absorber layer by means of a plasma etching process.
This is how the actual photomask is produced. To be able to use it as a tool, extensive cleaning and measuring steps are carried out to guarantee dimensional accuracy and defect-free production. At this point, the structures on the mask are measured optically and with electron beam microscopes, examined for defects with the help of complex inspection equipment and repaired if necessary. This takes up a large part of the production time. After the mask has been given a protective film, it is carefully inspected again by our employees and then leaves the AMTC for semiconductor factories all over the world.
The following methods are used for the photomask manufacturing process:
- Data Processing
- Electron Beam Writing
- Laser Beam Writing
- Wet Chemical Resist Development
- Plasma Etching
- Optical AFM and Electron Beam Measurement
- Inspection Laser and Ion Beam Repair
- Ion Induced Deposition
- Pellicle Assembly