. Photolithography is a critical process in integrated circuit (IC) manufacturing and accounts for 40%–50% of the process time in chip manufacturing. The photolithography process requires not only a lithography machine but also a key material: photoresist. Photoresist is one of the most critical materials in the semiconductor industry. In the overall integrated circuit manufacturing process, photolithography accounts for about 35% of total chip manufacturing cost and is the core process in semiconductor manufacturing. Photoresist is a complex mixture mainly composed of organic solvents, polymer resins, photoacid generators (PAG) and additives.
Among them, the photoacid generator is a key component of photoresist and plays a decisive role in photosensitivity and resolution. The purity and impurity control of photoacid generators have an important impact on photoresist quality and overall semiconductor product yield. A common photoacid generator consists of a triphenylsulfonium cationic part and a polyfluorinated sulfonate anionic part. The anionic part has almost no UV absorption, while the Charged Aerosol Detector (CAD) does not rely on optical activity of the compound, making it an ideal detector for controlling photoacid generator quality. Click to view full text.