Photo Acid Generators (PAGs)

Continued miniaturization of microchips and ever-evolving computing power of semiconductors increase the demands in the photolithographic process. PAGs from Heraeus Epurio offer unique characteristics for critical layer resists.

Photo Acid Generators (PAGs)

The computing power available to send the first man to the moon in 1969 was less than that available to each of us today on our smartphones. This incredible advance has been made possible by the miniaturization of microchips and the ever-evolving computing power of semiconductors.

The rise in wireless connectivity, sophisticated automotive features or the internet of things are reflected in the rise of demand for semiconductors capable of meeting the highest requirements. Ultra-pure speciality chemicals are the basic raw materials used in the photolithography process which forms the critical layer in the productions of memory and logic chips.

Hereaus Epurio, formerly known as Heraeus Daychem, has been producing electronic grade photoactive materials in Dayton, Ohio, for over 30 years. We have put together selected chromophores with vintage acids to create a unique product offering for critical layer resists in highest resolution.

Most of these products are available in UP quality boasting an above 99.5% purity and a metal content of all 26 metals below 10ppb each. This makes even conventional chemistry available for new frontiers in resist resolution.

At Heraeus, we take your needs very seriously. We always strive to find the best possible solution for your business in close cooperation with you. We offer small and large volumes and help you scale up production whilst safeguarding your intellectual property.

i-line and broadband PAG

There is a marked growing demand for highly sensitive, good soluble i-line PAGs for various chemical amplified resist application. To meet this demand, Heraeus Epurio has developed a set of i-line, broadband and even g-line products.

Purity is based on the proven electronic grade quality of Heraeus Epurio. In production, most of our PAGs can be scaled-up cost efficiently to up to tons, making them attractive for semiconductor packaging as well as display resists.

Weak acid PAG

Sensitive resins systems need weak acids. Heraeus Epurio offers proven sensitive chromophore-weak acid combinations as cost effective alternatives to existing systems. This product range consistently meets the highest purity and quality requirements.

Thermal acid generator

In order to meet the demand for thicker film resist, a growing number of formulations contain thermal acid generators to enable final curing during post-baking. Heraeus Epurio provides an IP-free set of products with various acid-releasing temperatures. For the final application, semiconductor-grade purity and cost efficiency are of the highest importance.


Based on patent-free technology, Heraeus produces and sells highly sensitive, thermostable and color-neutral photoinitiators with good solubility in common resist solvents. These have been qualified by major resist producers and offer a cost-effective solution to display resist and semiconductor packaging resist formulations.