Hollow-beam apertures for charged-particle-beam microlithography apparatus and methods for making and using same

A hollow-beam aperture for a charged-particle-beam microlithography apparatus, comprising:

• a first member defining a cutout having a radial dimension;
• a cylindrical beam-absorbing member having an axis and a radius relative to the axis, the radius of the beam-absorbing member being smaller than the radial dimension of the cutout;
• multiple support bars supporting the beam-absorbing member relative to the first member and concentrically with the cutout such that the axis of the beam-absorbing member is perpendicular to the plane of the first member, and the beam-absorbing member extends through the cutout, thereby forming a substantially annular aperture between the beam-absorbing member and the first member;
• and
• a second member defining a circular cutout having a radius no larger than the radial dimension of the cutout in the first member and larger than the radius of the beam-absorbing member, the second member being configured to be attached superposedly to the first member such that the cutout of the second member is coaxial with the beam-absorbing member, and the beam-absorbing member also extends through the second cutout.

A hollow-beam aperture, comprising:

• a main body defining a circular opening having an axis and a radius;
• a beam-absorbing body situated concentrically relative to the circular opening and connected to the main body by at least one support bar contiguous with the main body and the beam-absorbing body, the beam-absorbing body having a radius that is smaller than the radius of the circular opening;
• and
• the main body defining at least one void situated relative to the circular opening and the beam-absorbing body, the void being configured so as to cause the circular opening and beam-absorbing body to define a substantially annular beam-transmitting aperture, when the hollow-beam aperture is viewed along the axis, extending through the main body and concentric with the beam-absorbing body.

A method for manufacturing a hollow-beam aperture for use in a charged-particle-beam (CPB) microlithography apparatus, comprising:

• (a) providing a main body made of a CPB-absorbing material;
• (b) on a first surface of the main body, machining a circular opening having an axis and a radius;
• (c) on a second surface of the main body opposite the first surface, machining the main body to define a beam-absorbing body concentrically relative to the circular opening, the beam-absorbing body having a radius smaller than the radius of the circular opening, the circular opening and the beam-absorbing body each having a relatively thick dimension in a beam-transmission direction and being separated from each other by a portion of the main body that is relatively thin in the beam-transmission direction;
• and
• (d) machining the main body to define at least one void situated relative to the circular opening and the beam-absorbing body, the void being configured so as to cause the circular opening and the beam-absorbing body to define a beam-transmitting aperture that is concentric with the beam-absorbing body and substantially annular in profile when viewed along the axis, the beam-transmitting aperture extending through the portion of the main body, between the beam-absorbing body and the circular opening, that is relatively thin in the beam-transmission direction.

A method for manufacturing a hollow-beam aperture for use in a charged-particle-beam (CPB) microlithography apparatus, comprising:

• (a) providing a main body made of a CPB-absorbing material;
• (b) on a first surface of the main body, machining an annular opening having an axis and a radius, and defining a beam-absorbing body having a radius smaller than the radius of the annular opening, the annular opening and the beam-absorbing body each having a relatively thick dimension in a beam-transmission direction and being separated from each other by a portion of the main body that is relatively thin in the beam-transmission direction;
• and
• (c) machining the main body to define at least one void situated relative to the annular opening and the beam-absorbing body, the void being configured so as to cause the annular opening and the beam-absorbing body to define a beam-transmitting aperture that is concentric with the beam-absorbing body and substantially annular in profile when viewed along the axis, the beam-transmitting aperture extending through the portion of the main body, between the beam-absorbing body and the annular opening, that is relatively thin in the beam-transmission direction.