Photolithography is a key process in integrated circuit (IC) manufacturing, accounting for 40%–50% of the chip manufacturing process time. 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. Throughout the entire IC manufacturing process, the photolithography process accounts for approximately 35% of the 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 these, the photoacid generator is a key component of photoresist, playing a decisive role in the photosensitivity and resolution of the photoresist. The purity and impurity control of the photoacid generator have a significant impact on the yield of photoresist and the entire semiconductor product. The common composition of photoacid generators includes a triphenylsulfonium cation part and a polyfluorosulfonate anion part. The anion part has essentially no UV absorption. The charged aerosol detector (CAD) does not rely on the compound having optical activity and can be an ideal detector for controlling the quality of photoacid generators. Click to read full article