Patent Number: 
Section: claims

1. A stencil mask for limiting an irradiation area of charged particles on a surface of a substrate to a predetermined closed loop shape, the stencil mask comprising:a first layer disposed at a side of the stencil mask which faces toward the substrate; anda second layer disposed at a side of the stencil mask to which the charged particles are irradiated, wherein:at least one first penetrating hole having the predetermined closed loop shape is formed in the first layer;a plurality of second penetrating holes is formed in the second layer within a distributing area encompassing the predetermined closed loop shape, the plurality of the second penetrating holes being distributed within the distributing area; anda portion of the second layer separating at least one pair of adjacent second penetrating holes crosses a limited portion of the first penetrating hole when viewed along the traveling path of the charged particles. 2. The stencil mask according to claim 1,wherein the distributing area of the second penetrating holes is larger than the shape of the first penetrating hole when viewed along the traveling path of the charged particles. 3. The stencil mask according to claim 1,wherein the first layer and the second layer are made of semiconductor material, and the first layer and the second layer are in contact with each other. 4. The stencil mask according to claim 1,wherein the portion of the second layer separating at least one pair of adjacent second penetrating holes connects portions of the first layer separated by the first penetrating hole. 5. The stencil mask according to claim 1,wherein each of the second penetrating holes has a convex polygonal shape. 6. The stencil mask according to claim 1,wherein a distance between at least one pair of adjacent second penetrating holes is longer at the side of the second layer to which the charged particles are irradiated than at the side of the second layer facing toward the first layer. 7. A device for irradiating charged particles, comprising:a charged particle generator;a mass analyzer for selecting predetermined charged particles from the charged particles generated by the generator;an accelerator for accelerating the selected charged particles;an irradiating chamber for accepting a substrate, andthe stencil mask according to claim 1 disposed between the accelerator and the substrate being accepted within the irradiating chamber. 8. A method of using a stencil mask, comprising:disposing the stencil mask of claim 1 above a substrate; andirradiating charged particles through the stencil mask to the surface of the substrate. 9. A method of manufacturing a semiconductor device, comprising:disposing the stencil mask of claim 1 above a semiconductor wafer; andirradiating charged particles through the stencil mask to the surface of the semiconductor wafer. 10. A stencil mask for limiting an irradiation area of charged particles on a surface of a substrate to a predetermined closed loop shape with an island portion located within the closed loop, the stencil mask comprising:a first layer disposed at a side of the stencil mask which faces toward the substrate; anda second layer disposed at a side of the stencil mask to which the charged particles are irradiated, wherein:at least one first penetrating hole having the predetermined closed loop shape with the island portion located within the closed loop is formed in the first layer; andat least a portion of the second layer crosses a limited portion of the first penetrating hole and connects the island portion and a portion of the first layer surrounding the first penetrating hole when viewed along the traveling path of the charged particles.