HORIBA Advanced Techno. Co. Ltd. recently launched the CS-620F, a fiber optic type hot phosphoric acid concentration monitor. The device keeps track of the concentration of phosphoric acids used in the semiconductor manufacturing process, mainly in the silicon nitride layer etching process for 3D NAND flash 
Source: HORIBA Advanced Techno. Co. Ltd.memory.
Previously, it was necessary to cool high-temperature phosphoric acids before measuring their concentration. When using perfluoroalkoxy resin in the sample measuring unit, the CS-620F measures the concentration of a chemical solution without the need to cool it; this renders the cooling mechanism and cooling time unnecessary, thus enhancing the efficiency of the semiconductor manufacturing process via concentration control of high-temperature, highly concentrated phosphoric acids.
The monitor measures phosphoric acid concentrations in the 140° C to 170° C temperature range, providing real-time information by updating data every three seconds. The CS-620F only needs to be calibrated once every six months, significantly reducing instrument downtime.
