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 highly selectively etched as compared with 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: 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: A method of manufacturing a stacked structure includes forming a first metal buffer layer including crystal grains on a base substrate, forming a second metal buffer material layer on the first metal buffer layer, and crystallizing the second metal buffer material layer to form a second metal buffer layer, wherein the second metal buffer material layer includes crystal grains, and a density of the crystal grains of the second metal buffer material layer is lower than a density of the crystal grains of the first metal buffer layer.

Abstract: The present invention relates to a dual venturi for a combustor and, specifically, to a dual venturi for a combustor, which adjusts the amount of gas and air supplied to a burner of a hot water heater and has a motor combined with a damper in order to increase a turn-down ratio (TDR), such that the damper is rotated by the driving of the motor so as to simultaneously open or close secondary air and gas inlets, thereby enabling efficient heating control. The present invention has a separate opening/closing means which is capable of controlling, in two stages, the amount of air and gas flowing into the combustor such as the hot water heater, wherein the opening/closing means comprises the motor and the damper, and the damper is rotated by the driving of the motor so as to simultaneously open or close the secondary air and gas inlets, thereby enabling the control of the amount of air and gas.

Abstract: The present invention relates to a combustion apparatus having an intake air/exhaust air heat exchanger. The combustion apparatus comprises: a burner for generating exhaust gas; a blower for supplying external air to the burner; a main heat exchanger for absorbing heat from the exhaust gas generated by the burner; an exhaust gas duct for discharging the exhaust gas having passed the main heat exchanger to the outside; an intake air duct for introducing external air to the blower; an intake air/exhaust air heat exchanger for exchanging heat between the external air introduced to the blower and the exhaust gas discharged through the exhaust gas duct using a thin film plate disposed therebetween; and an exhaust flue for discharging the exhaust gas having passed the intake air/exhaust air heat exchanger to the outside.

Abstract: The present invention relates to a dual venturi for a combustor and, specifically, to a dual venturi for a combustor, which adjusts the amount of gas and air supplied to a burner of a hot water heater and has a motor combined with a damper in order to increase a turn-down ratio (TDR), such that the damper is rotated by the driving of the motor so as to simultaneously open or close secondary air and gas inlets, thereby enabling efficient heating control. The present invention has a separate opening/closing means which is capable of controlling, in two stages, the amount of air and gas flowing into the combustor such as the hot water heater, wherein the opening/closing means comprises the motor and the damper, and the damper is rotated by the driving of the motor so as to simultaneously open or close the secondary air and gas inlets, thereby enabling the control of the amount of air and gas.