公开(公告)号：US20180007771A1

公开(公告)日：2018-01-04

申请号：US15697915

申请日：2017-09-07

Applicant: Gigaphoton Inc.

Inventor： Kouichi SATOU ,  Takayuki YABU ,  Yoshifumi UENO ,  Hirokazu HOSODA

IPC: H05G2/00 ,  H01S3/10

CPC classification number: H05G2/008 ,  G21K2201/06 ,  H01S3/10 ,  H05G2/005 ,  H05G2/006

Abstract: The stability of operations of an EUV light generating apparatus is improved. A droplet detector may include: a light source unit configured to emit illuminating light onto a droplet, which is output into a chamber and generate extreme ultraviolet light when irradiated with a laser beam; a light receiving unit configured to receive the illuminating light and to detect changes in light intensities; and a timing determining circuit configured to output a droplet detection signal that indicates that the droplet has been detected at a predetermined position within the chamber, based on a first timing at which the light intensity of the illuminating light decreases due to the droplet being irradiated therewith and a second timing at which the light intensity of the illuminating light increases.