Patent ID: 6618403
Filing Date: 2003-09-09
Classification: H01S

Abstract:
A lithography laser system for incorporating with a semiconductor processing system that includes beam shaping optical elements, comprising:a discharge chamber filled with a laser gas including molecular fluorine and a buffer gas; a plurality of electrodes within the discharge chamber and connected with a discharge circuit for energizing the laser gas; a resonator including the discharge chamber for generating a laser beam, wherein the laser beam exits the laser system and passes through the beam shaping optical elements of the semiconductor processing system; and a processor for running an energy control algorithm and sending a signal to the discharge circuit based on said algorithm to apply electrical pulses to the electrodes so that the laser beam exiting the laser system and before entering the beam shaping optical elements has a specified first energy distribution over a plurality of pulses that results in a substantially constant energy of the laser beam exiting the beam shaping optical elements, and wherein said energy control algorithm is based upon a second energy distribution of the laser beam previously determined of a substantially same pattern of pulses as said plurality of pulses having said first energy distribution, said second energy distribution being determined after the laser beam passes through the beam shaping optical elements while the energy of the laser beam exiting the laser system and entering the beam shaping optical elements is maintained at an approximately constant first energy.