Patent ID: 7307259
Filing Date: 2007-12-11
Classification: G01N,G03F,H01L,Y10T

Abstract:
1. A system for controlling a composition for a lithography process in real time, comprising: a composition circulator for withdrawing the composition from a storage tank retaining the composition for a lithography process, and for recycling the withdrawn composition to the storage tank, through a flow cell; a composition analyzer for measuring an absorbance of the composition passing through the flow cell, and for calculating the concentration of at least one component of the composition from the measured absorbance; a component supplier for supplying a deficient component to the storage tank when a concentration of the deficient component is below a predetermined level; and a controller for controlling the component supplier to adjust the concentration of each component of the composition according to the absorbance, wherein the composition circulator comprises: a first automatic valve, which is installed on the storage tank retaining the composition, for withdrawing the composition from the storage tank; a transfer vessel for receiving the composition withdrawn from the storage tank through the first automatic valve, and for transferring the received composition to the flow cell; and a vacuum reservoir for vacuumizing the transfer vessel, wherein the composition circulator further includes a vacuum ejector for vacuumizing the vacuum reservoir by receiving air and ejecting air therefrom according to the control of a second automatic valve.