Process procedure photoresists

When new and clean substrates (wafers) are used, a heating at approximately 200 °C for several minutes (2-3 min, hot plate) is sufficient for drying. Substrates should however subsequently be processed quickly.

Process procedure e-beam resist

Process procedure e-beam resist
Development of PMMA films PMMA films can only be developed with solvent-based developers. Aqueous-alkaline PMMA developers will not attack PMMA – PMMA is even used as protective coating in the presence of strongly alkaline solutions.

UV-curing

Photoresist structures of standard resists possess a softening point of 115 – 130 °C. During subsequent thermal processes (plasma etching, sputtering or others), these temperatures are easily exceeded.

Principle and functioning

Positive resist The addition of photoactive compounds (PACs, naphthoquinone diazide (NQD)) to alkali-soluble novolacs reduces the alkali-solubility of resists films.

Other resist components

Solvents are the main component of all resists, with solvent contents ranging from 50% (thick resists) to up to 99% (spray resists).

Composition of photoresists

Photoresists are particularly employed in microelectronics and in microsystems technology to generate µm- and sub-µm structures.

Photosensitive components

The p hoto sensitive components of our positive photoresists belong to the group of naphtho qu inone d iazides (NQD).

Cross linker

The patterning of negative resists is based on the stabilization of exposed areas in the presence of cross-linking agents. Radical starters like e.g. azo-bis(isobutyronitrile) (AIBN)

Storage and ageing

Photoresists are light-sensitive, their properties change in the presence of light or elevated temperatures. Resists age during storage and are therefore supplied in light-protected amber glass bottles,