US 10,172,224 B2
Extreme UV light generator
Takayuki Yabu, Oyama (JP); Hirokazu Hosoda, Oyama (JP); and Takuya Ishii, Oyama (JP)
Assigned to Gigaphoton Inc., Tochigi (JP)
Filed by Gigaphoton Inc., Tochigi (JP)
Filed on Nov. 15, 2016, as Appl. No. 15/351,988.
Application 15/351,988 is a continuation of application No. PCT/JP2015/070740, filed on Jul. 21, 2015.
Claims priority of application No. PCT/JP2014/069715 (WO), filed on Jul. 25, 2014.
Prior Publication US 2017/0064799 A1, Mar. 2, 2017
Int. Cl. H05G 2/00 (2006.01); G03F 7/20 (2006.01); G21F 3/00 (2006.01)
CPC H05G 2/006 (2013.01) [G03F 7/70033 (2013.01); G21F 3/00 (2013.01); H05G 2/008 (2013.01)] 20 Claims
OG exemplary drawing
 
1. An extreme ultraviolet light generation apparatus comprising:
a chamber in which extreme ultraviolet light is generated from plasma, the plasma being generated by irradiating a target supplied into the chamber with a laser beam;
a target generator configured to supply the target into the chamber as a droplet;
a droplet measurement unit configured to measure the droplet supplied from the target generator into the chamber; and
a shielding member configured to shield the droplet measurement unit from electromagnetic waves emitted from the plasma,
the droplet measurement unit including:
a light source configured to emit continuous light to the droplet;
a window provided in the chamber and configured to allow the continuous light to transmit therethrough; and
an optical sensor configured to receive the continuous light via the window, and
the shielding member including a shielding body provided on the chamber side with respect to the window configured to cover an optical path of the continuous light and having a light passing opening for passing the continuous light therethrough, and the shielding member is provided within the interior of the chamber, configured separately from a wall that constitutes the chamber.