Foil trap and extreme ultraviolet light source device using the foil trap

FOREIGN PATENT DOCUMENTS

DE 102 37 901 B3 5/2004

EP 1 365 636 A1 11/2003

EP 1 742 110 A2 1/2007

JP 2007-5124 A 1/2007

JP 2007-5542 A 1/2007

WO 2006/134512 A2 12/2006
OTHER PUBLICATIONS

Present Status and Future of EUV (Extreme Ultra Violet) Light
Source Research, Mizoguchi Hakaru, Research Division,
Gigaphoton Ltd., J.Plasma Fusion Res., vol. 79, No. 3 (2003) pp.
219-262.

* cited by examiner

Primary Examiner * Phillip A Johnston
(74) Attorney, Agent, or Firm * Roberts Mlotkowski Safran
& Cole, P.C.; David S. Safran

(57) ABSTRACT

An extreme ultraviolet (EUV) light source device and foil trap, the device including a vessel; an EUV radiating species supply means that feeds an extreme ultraviolet radiating species into the vessel; a discharge part with discharge electrodes that heat and excite the EUV radiating species and generate a high-temperature plasma; a collector mirror collecting EUV radiation emitted from the plasma; the foil trap installed between the discharge part and the mirror; an extractor part extracting the collected radiation; and an evacuation means exhausting and regulating pressure within the vessel. The foil trap includes foils extending radially from a main axis thereof to capture debris from the light source, while allowing the emitted radiation to pass through a region thereof to the mirror. A length of at least part of the foils in directions parallel to the main axis is shorter in positions close to the main axis than distant therefrom.

6 Claims, 14 Drawing Sheets

(1 I (i) b
/
a
15a
15a
Main axis C
(optical axis) - — —
I 0| 0| 5 I5 8
-1—> -4—-—>
Foil Width L Foil Width L

Conventional foil Width

1 5a 8 - , ‘ \ Fig 2(a) l\_\\ f/_',i€;* H /T j 4; ¢ 1/1" MM \ ““ ‘ ‘\ Optical axis Foil width L 15a 8 " Fig ---i-T-_-Tr:-===——:-;-;-:_=;Ti§ii@_@_amlaim/:t;—:a%?2::f-/—:—i — — — — F — -- — _i / //_:?<~\M,,_, \ i \ I l//»'-” "J, Optical axis ‘/1 ) <—||L _ 88 15 8 Fig. 2(c) ‘\ aw ________________ 4, /7 ( 1"‘ Optical axis 4——I

15a Fig. 3(a) / __ Position of radiation incidence side _______\_~_ \\ \ I I I I /J I I I I Emission 15d 8 angle \ Distance from 15 plasma 15a Position of radiation incidence _ side in this application Flg. 3(b)

Position of EUV radiation incidence when length of foil in direction of optical axis is constant

\F-/

15d

I