Abstract: An apparatus and a method for stripping silicon nitride are disclosed that facilitate automatic, real-time, and exact measurement of etch rate and an ending time of the etching process when silicon nitride is stripped with phosphoric acid solution. The method for stripping silicon nitride includes the steps of: a) measuring initial concentration of a specific ion in a phosphoric acid solution contained in a reactor, b) dipping a silicon nitride-formed substrate into the phosphoric acid solution in the reactor, c) measuring instantaneous concentration of the specific ion in stripping solution extracted from the reactor when silicon nitride stripping is processed in the reactor, and d) finishing the silicon nitride stripping process if variation rate of the measured instantaneous concentration is not exceeding a predetermined standard, or returning to the step c) if the variation rate is more than the predetermined standard.

Abstract: An apparatus and a method for stripping silicon nitride are disclosed that facilitate automatic, real-time, and exact measurement of etch rate and an ending time of the etching process when silicon nitride is stripped with phosphoric acid solution. The method for stripping silicon nitride includes the steps of: a) measuring initial concentration of a specific ion in a phosphoric acid solution contained in a reactor, b) dipping a silicon nitride-formed substrate into the phosphoric acid solution in the reactor, c) measuring instantaneous concentration of the specific ion in stripping solution extracted from the reactor when silicon nitride stripping is processed in the reactor, and d) finishing the silicon nitride stripping process if variation rate of the measured instantaneous concentration is not exceeding a predetermined standard, or returning to the step c) if the variation rate is more than the predetermined standard.

Abstract: A method of pre-cleaning a wafer for gate oxide formation is described. In the method, a wafer is loaded into a cleaning bath, and a cleaning agent such as diluted HF is supplied into the bath so as to remove contaminants from the back surface of the wafer. Then the cleaning agent is drained from the bath, and the wafer is rinsed with DI water. During this DI rinsing step, contaminants removed from the wafer may remain as impurities and bind to or combine with silicon on the front surface of the wafer. To remove such impurities from the wafer, a second cleaning agent is supplied again into the bath. After removal, the second cleaning agent is drained from the bath, and the wafer is rinsed again with DI water. Finally, and optionally, the wafer may be treated with HCl and ozone.

Abstract: A method of forming a shallow trench isolation is disclosed. An example method of forming a shallow trench isolation performs a planarization process for a substrate on which a hard mask and an insulation layer are formed, selectively etching the insulation layer on the edge of the substrate by using wet etch equipment, and performs a main etching process in the center region of the substrate.

Abstract: A method of forming a shallow trench isolation is disclosed. An example method of forming a shallow trench isolation performs a planarization process for a substrate on which a hard mask and an insulation layer are formed, selectively etching the insulation layer on the edge of the substrate by using wet etch equipment, and performs a main etching process in the center region of the substrate.