PLASMA LIGHT SOURCE

• Main Authors: HORIOKA KAZUHIKO, SODEKODA TATSUYA, KUWABARA HAJIME, KAWASAKI TOMOAKI
• Format: Patent
• Language: English; Japanese
• Published: 22.02.2018
• Subjects: APPARATUS SPECIALLY ADAPTED THEREFOR; CINEMATOGRAPHY; ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; ELECTROGRAPHY; HOLOGRAPHY; MATERIALS THEREFOR; ORIGINALS THEREFOR; PHOTOGRAPHY; PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES,e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTORDEVICES; PHYSICS; X-RAY TECHNIQUE

PROBLEM TO BE SOLVED: To decrease a difference in the approach time of initial plasma moving from both sides in an axial direction to collide, and to increase an emission amount of extreme ultraviolet light.SOLUTION: A plasma light source 1 includes a pair of coaxial electrodes 10 opposing to each other over a central plane P. The coaxial electrode 10 includes a center electrode 11 extending in a direction orthogonal to the central plane P and a plurality of external electrodes 12 extending toward the central plane P and spaced from one another in a circumference direction of a virtual circle centering an axis A of the center electrode 11. The plasma light source 1 includes: a plasma medium holding part for holding a plasma medium and disposed outside a virtual line on the central line P and connecting external electrodes 12 adjoining in the circumference direction; a laser irradiation part 31 for irradiating a plasma medium held by the plasma medium holding part with laser light; and a restriction part 51 disposed between the plasma medium holding part and the external electrode 12 in a radial direction and restricting directions of diffusion of medium vapor vaporized in the plasma medium holding part.SELECTED DRAWING: Figure 1 【課題】軸線方向の両側から移動して衝突する初期プラズマの到達時間のずれを低減して、極端紫外光の発光量を増大させる。【解決手段】プラズマ光源１は、中央面Ｐを挟んで対向する一対の同軸状電極１０を備える。同軸状電極１０は、中央面Ｐと直交する方向に延在する中心電極１１と、中心電極１１の軸線Ａを中心とする仮想円の周方向に離間し、中央面Ｐに向かって延在する複数の外部電極１２と、を備える。プラズマ光源１は、中央面Ｐ上であり、周方向に隣り合う外部電極１２を結ぶ仮想線よりも外側に配置され、プラズマ媒質を保持するプラズマ媒質保持部と、プラズマ媒質保持部に保持されたプラズマ媒質にレーザを照射するレーザ照射部３１と、径方向において、プラズマ媒質保持部と外部電極１２との間に配置され、プラズマ媒質保持部で蒸発した媒質蒸気が拡散する方向を制限する制限部５１と、を備える。【選択図】図１