Abstract: A method for manufacturing high purity sulfuric acid is provided. A mixed solution subsequently undergoes a first preheating step, a second preheating step, a distilling step and an evaporating step to remove peroxide, water, oxygen and insoluble impurities, so as to obtain the first gas containing sulfur trioxide, sulfuric acid and hydrogen oxide. And then, the sulfur trioxide is absorbed by a sulfuric acid solution, thereby forming the high purity sulfuric acid.

Abstract: A method for manufacturing high purity sulfuric acid is provided. A mixed solution subsequently undergoes a first preheating step, a second preheating step, a distilling step and an evaporating step to remove peroxide, water, oxygen and insoluble impurities, so as to obtain the first gas containing sulfur trioxide, sulfuric acid and hydrogen oxide. And then, the sulfur trioxide is absorbed by a sulfuric acid solution, thereby forming the high purity sulfuric acid.

Abstract: A method for manufacturing high purity sulfuric acid is provided. A mixed solution subsequently undergoes a first preheating step, a second preheating step, a distilling step and an evaporating step to remove peroxide, water, oxygen and insoluble impurities, so as to obtain the first gas containing sulfur trioxide, sulfuric acid and hydrogen oxide. And then, the sulfur trioxide is absorbed by a sulfuric acid solution, thereby forming the high purity sulfuric acid.

Abstract: A method for manufacturing high purity sulfuric acid is provided. A mixed solution subsequently undergoes a first preheating step, a second preheating step, a distilling step and an evaporating step to remove peroxide, water, oxygen and insoluble impurities, so as to obtain the first gas containing sulfur trioxide, sulfuric acid and hydrogen oxide. And then, the sulfur trioxide is absorbed by a sulfuric acid solution, thereby forming the high purity sulfuric acid.

Abstract: An electrodialysis method for the treatment of silicate-containing potassium hydroxide etching waste solution is provided. The method comprises: providing a reaction tank including a cathode, an anode, and two cation dialysis membranes, wherein the reaction tank is divided by the cation dialysis membranes into a cathode chamber, an anode chamber and a waste solution disposing chamber located therebetween; filling a sulfuric acid solution into the anode chamber; filling a potassium hydroxide solution into the cathode chamber; introducing a silicate-containing potassium hydroxide etching waste solution into the waste solution disposing chamber; and applying a voltage and a current density to each of the chambers to render potassium ions to transport from the waste solution chamber through the cation dialysis membrane to the cathode chamber.

Abstract: An electrodialysis method for the treatment of silicate-containing potassium hydroxide etching waste solution is provided. The method comprises: providing a reaction tank including a cathode, an anode, and two cation dialysis membranes, wherein the reaction tank is divided by the cation dialysis membranes into a cathode chamber, an anode chamber and a waste solution disposing chamber located therebetween; filling a sulfuric acid solution into the anode chamber; filling a potassium hydroxide solution into the cathode chamber; introducing a silicate-containing potassium hydroxide etching waste solution into the waste solution disposing chamber; and applying a voltage and a current density to each of the chambers to render potassium ions to transport from the waste solution chamber through the cation dialysis membrane to the cathode chamber.

Abstract: This invention is a method for cleaning a semiconductor manufacturing system, which passes a highly volatile liquid agent through the system to remove the impurities and to dissolve chemicals used in the system. The cleaning agent dissolves and washes the chemicals out of the system to keep the chemicals from combining with moisture in the air and forming oxide particles. By washing with a liquid, residual gases and impurities in the system are rapidly removed from the system. After washing the system, the cleaning agent is quickly dried because the cleaning agent is highly volatile. Thereby, the system is cleaned efficiently within a short time by using this method.

Abstract: This invention relates to a method for detecting quantity variation of high purity liquid chemicals by way of detecting capacitance variation to determine the liquid level of liquid chemicals. Meanwhile, the ratio of the area of the smallest electrode of the capacitor to the distance between the electrodes is adjusted to magnify the capacitance so that a very small variation can be observed clearly. This invention also discloses a device to carry out this method.

Abstract: This invention relatives to a method for detecting quantity variation of high purity liquid chemicals by way of detecting capacitance variation to determine the liquid level of liquid chemicals. Meanwhile, the ratio of the area of the smallest electrode of the capacitor to the distance between the electrodes is adjusted to magnify the capacitance so that a very small variation can be observed clearly. This invention also discloses a device to carry out this method.