Two-layer resist system for hydrofluoric acid etching

Hydrofluoric acid etchings, even those in highly concentrated acids (48%), are technologically used despite the high risk involved with HF applications.

Protective coating for KOH-etching

Protective coatings AR-PC 503 and 504 are able to withstand the presence of 40%, 85°C warm KOH for several hours. The polymer PMMA is not attacked under these conditions. These resists can consequently be used to protect front and back surface of wafers during deep silicon etching.

Alkali-stable and solvent-stable negative resist

Most novolac-based photoresists are characterized by high etch stability in the presence of acids (except in highly concentrated oxidizing acids or in concentrated hydrofluoric acid

Temperature-stable negative resist

New aqueous-alkali soluble polymers may even outperform novolacs in certain features. Standard novolacs generally melt in a range between 115–130°C. The thicker the resist film, the higher is the impact of this feature on the resist structure.

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).

Ageing of developer

Aqueous-alkaline developers are subjected to ageing, due to an uptake of CO 2 from the air. Buffered aqueous-alkaline developers ( AR 300-26, -35 ) are more stable in this respect than developers of the AR 300-40 -series containing TMAH.

Positive polyimide resist for e-beam-lithography

First experiments with our SX AR-P 5000/82.7 using e-beam lithography clearly demonstrated that this resist can easily be patterned which offers the possibility to generate nanostructures which are thermally stable up to 350 °C.

High-resolution negative e-beam resist

A process-stable, sufficiently sensitive e-beam resist with a resolution of about 30 nm is urgently needed to accelerate the progress in electron beam lithography.

Lift off (one layer – two layer)

Two procedures are principally possible to manufacture e.g. conducting paths: 1. Etching technique: A thin metal film (e.g. aluminium) is deposited on a wafer (evaporation or sputtering)

Composition of photoresists

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