Abstract: Provided are a silicon nitride film etching composition, a method of etching a silicon nitride film using the same, and a manufacturing method of a semiconductor device. Specifically, a silicon nitride film may be stably etched with a high selection ratio relative to a silicon oxide film, and when the composition is applied to an etching process at a high temperature and a semiconductor manufacturing process, not only no precipitate occurs but also anomalous growth in which the thickness of the silicon oxide film is rather increased does not occur, thereby minimizing defects and reliability reduction.

Abstract: An OFDM receiver system for performing precise OFDM demodulation is provided. The OFDM receiver system performs demodulation by sharing memories and operators in a time-divisional manner. FFT-processed data is separated into specific pilot signals and data according to the timing indicated by a controller to then be rearranged and stored, thereby facilitating extraction of corresponding pilot signals and data for various synchronization and equalization steps. Therefore, the demodulation system having an optimal structure can be realized in view of resource utilization efficiency and chip areas, the cost and time for fabricating and designing the system can be reduced, and verification of the system can be easily performed.