US Patent No. 10,342,109

APPARATUS AND METHOD FOR GENERATING EXTREME ULTRAVIOLET RADIATION


Patent No. 10,342,109
Issue Date July 02, 2019
Title Apparatus And Method For Generating Extreme Ultraviolet Radiation
Inventorship Wei-Chih Lai, Changhua County (TW)
Han-Lung Chang, Kaohsiung (TW)
Bo-Tsun Liu, Taipei (TW)
Li-Jui Chen, Hsinchu (TW)
Po-Chung Cheng, Chiayi County (TW)
Assignee TAIWAN SEMICONDUCTOR MANUFACTURING CO., LTD., Hsinchu (TW)

Claim of US Patent No. 10,342,109

1. A device for controlling an excitation laser in an extreme ultraviolet (EUV) radiation source, the EUV radiation source comprising a droplet generator configured to generate target droplets and the excitation laser configured to heat the target droplets using excitation pulses, the device comprising:a first radiation source configured to irradiate each of the target droplets at a first position;
a second radiation source configured to irradiate each of the target droplets at a second position a fixed distance away from the first position;
a droplet detector configured to detect a first signal of radiation scattered by a given target droplet at the first position and a second signal of radiation scattered by the given target droplet at the second position; and
a timing module configured to receive the first signal and the second signal, measure a speed of the given target droplet based on the received signals, estimate a trigger time for providing an excitation pulse to heat the given target droplet based on the measured speed and provide the excitation laser the trigger time.