Abstract: The present invention relates to methods of predicting proximity heating of resists in electron beam lithography in real-time as the writing proceeds enabling beam compensation in current and/or dwell time to be performed during writing. A method of using a precomputed kernel capable of proximity resist temperature evaluation in real-time as beam writing proceeds by scalar product of the kernel with a graded cell size coverage map. A shifted impulse response function is shown to give the kernel values accurate to within a few percent.

Abstract: The present invention relates to methods of predicting proximity heating of resists in electron beam lithography in real-time as the writing proceeds enabling beam compensation in current and/or dwell time to be performed during writing. A shifted impulse response function is shown to give proximity heating results accurate to within a few percent. A method of using a precomputed kernel capable of proximity resist temperature evaluation in real-time as beam writing proceeds.

Abstract: A shield assembly for reducing electron fogging effects in electron beam lithography. This shield, located between an electron beam column final aperture and the beam target, is of multiple vanes with sharp edges pointing towards the electron beam incident point on the target; the vanes are conically shaped and concentric around the electron beam path, which travels through the center of the assembly. Additionally, the sharp edges are such that they present oblique surfaces at the ends of the vanes angled between 10° and 20° relative to the outer vane surface and these oblique surfaces face towards the electron beam path. Furthermore, the shield assembly may also have the vanes angled towards the beam incident point such that the vertex of the conical vane assembly is coincident with the beam incident point.

Abstract: An acousto-optic modulator for use with a multi-channel laser beam system, for instance, is of conventional structure except that two different RF (radio frequency) signals drive the modulator. These signals each produce at least one output beam as diffracted by the modulator body. These two beams are angularly and spatially separated. One of the sets of beams is incident upon a beam stop, and therefore is not used for writing. Only the other set of beams, driven by the other of the frequencies, performs the actual writing. The optical stop in addition to blocking one of the sets of diffracted beams also blocks the transmission of the zero order (undiffracted) beam. The sum of the load power of the signals at the two frequencies is kept approximately constant, thereby maintaining a constant thermal condition within the modulator.

Abstract: A method and the associated apparatus for alignment and assembly of microlenses and microcolumns in which aligning structures such as rigid fibers are used to precisely align multiple microlens components. Alignment openings are formed in the microlens components and standard optical fibers are threaded through the openings in each microlens component as they are stacked. The fibers provide sufficient stiffness and stability to the structure to precisely align the apertures of the microlens components and thereby allow for increased assembly efficiency over traditional microlens and microcolumn bonding techniques.

Abstract: A movable stage assembly suitable for use in a vacuum has three circular stages rotating independently of one another. The stage assembly includes a base and a large rotatable circular table mounted on the base. This large table has a second smaller circular table which is eccentrically mounted within the first large table and rotates independently. This second table also has a smaller third circular table eccentrically mounted on it and independently rotatable within the second table. All the rotatable tables utilize ferrofluidic seals to prevent air within the air bearings from leaking into the vacuum chamber and are driven by motors mounted beneath the tables.

Abstract: An electron beam column (or other charged particle beam column) for lithography which exposes a surface to variable shapes in a raster scan. The beam column includes an electron (or ion) source that generates a charged particle beam, a transfer lens, an upper aperture, an upper deflector, a lower aperture, a lower deflector, magnetic deflection coils, and a beam objective lens. The beam is first shaped as a square in cross section by the upper aperture. The upper deflector changes the direction of the square shaped beam to pass through a specific portion of an opening defined in the lower aperture to shape the beam as desired. The lower aperture defines either a cross shaped opening or four L-shaped openings arranged as corners of a square. The combination of upper and lower apertures enable definition of exterior and interior corners as well as horizontal and vertical edges of a pattern, so that only one flash need be exposed in any one location on the surface.

Abstract: An optical mask for high resolution optical lithography using short wavelength light, e.g., 157 nm, uses membranes of a material that is transparent to the desired wavelength. The thin membranes are held under tensile stress by a supporting structure, such as a silicon wafer. Because the membranes are thin, the heating of the membrane material during generation of the overlying lithographic patterns is reduced. This is particularly advantageous when a material such as calcium fluoride is used as the transparent medium of the mask because calcium fluoride has a high thermal expansion coefficient. Thus, the membrane will suffer little distortion during the production of the mask. The lithographic pattern is produced using a thin layer of a absorptive material, such as palladium. Because both the absorptive material and the membrane are thin, there is little back scattering during the generation of the lithographic pattern by e-beam writing, and consequently, no proximity correction is necessary.

Abstract: A linear array of equal intensity optical beams is transformed into a rectangular array of equal intensity optical beams, while the intensity of each beam is kept nearly constant. The transformation is performed using an optical element which has two coatings on the front surface and a reflective coating on the opposing back surface. The front surface is partially coated with a reflective coating and partially coated with an anti-reflective coating. The beams are incident upon the front surface, with some of the beams incident on each of the two different coatings on the front surface. The beams incident on the front surface are specularly reflected. The remaining beams are transmitted through the optical element to the back surface, reflected from the back surface, and transmitted back up through the optical element and exit from the front surface. The exiting beams are thus shifted laterally and transversely to define the desired rectangular array.

Abstract: An improved compact tandem photon and electron beam lithography system includes a field lens adjacent the photoemission source which is utilized in combination with an objective lens to minimize field aberrations in the usable emission pattern and minimize the interaction between electrons to improve the throughput of the system. If desired, a demagnifying lens can be utilized between the field lens and the objective lens to increase the demagnification ratio of the system.

Abstract: A method for forming microcolumns in which laser spot welding bonds the multiple layers of an electron beam microcolumn. A silicon microlens is laser spot welded to a glass insulation layer by focusing a laser through the insulation layer onto the silicon microlens. The glass layer is transparent to the laser, allowing all of the energy to be absorbed by the silicon. This causes the silicon to heat, which, in turn, heats the adjacent surface of the glass insulation layer creating a micro-weld between the silicon and glass. The insulation layer includes a portion which protrudes beyond the edge of the first microlens so that when a second microlens is attached to the opposite side of the insulation layer, the second microlens can be laser spot welded to the protruding portion of the insulation layer by focusing a laser through the protruding portion of the insulation layer to heat the second microlens.