HF SUPPLY SYSTEM OF WET ETCHER

摘要

PURPOSE: A HF supply system of a wet etcher is provided to remarkably improve work efficiency and to prevent a defective wafer, by installing a density measurement unit for measuring the density of HF in a solution bath to which the wafer is loaded so that deionized water supplied to the inside of the solution bath after the wafer is etched by HF can easily be recognized. CONSTITUTION: HF is stored in a store tank(110). HF is supplied from the store tank to a mixture tank(120) wherein a predetermined ratio of deionized(DI) water is added to the HF. The mixture solution in the mixture tank is circulated along an arbitrary path outside the mixture tank. A constant temperature bath(130) uniformly controls the temperature of the mixture solution, installed in a position of the circulation path. Wafers(170) to etch are loaded to the solution bath(150) to which the mixture solution is supplied. An etch process is performed in the solution bath. The wafer is supported by a guide. The mixture solution is supplied to an HF supply unit(158). A DI water supply unit supplies the DI water to the inside of the solution bath. A sensor measures the quantity of the supplied solution. An exhaust unit(162) exhausts the solution in the solution bath. A density measurement unit(180) measures the density of HF in the solution bath. Whether the DI water is supplied to the solution bath is recognized by using the density measurement unit.