Patent ID: 8835870

Claim:
An ion generation target comprising: a substrate including a first surface and a second surface opposed to the first surface and a cone type hole, the cone type hole having a top surface and a bottom surface in the first surface and the second surface of the substrate, respectively, the cone type hole penetrating through the substrate such that a cross-sectional area of the cone type hole continuously decreases from the top surface to the bottom surface, the cross-sectional area parallel to the top and bottom surfaces of the cone type hole, the cone type hole further having a sidewall surface that has a reflectivity higher than that of the substrate; and an ion generation thin film attached to the second surface of the substrate such that a portion of the ion generation thin film contacts the bottom surface of the cone type hole, the ion generation thin film configured to generate ions when a laser beam incident through the top surface of the cone type hole strikes the contacting portion of the ion generation thin film, an intensity of the laser beam increasing when the laser beam penetrates through the cone type hole from the top surface to the bottom surface.