Abstract: A pedestal is formed over a first pole piece layer and insulator materials are formed to surround it. A gap layer made of a non-magnetic insulator or metal is then formed over the pedestal and the insulator, followed by the optional formation of a seed layer. A second pole piece is formed over the gap layer with or without the seed layer by forming a patterned resist using E-beam lithography and electroplating second pole piece materials within the patterned resist. After milling to remove side portions of the gap layer and the optional seed layer, a chemical etch is performed to remove a top portion of the insulator materials. The pedestal is then notched and trimmed by ion milling using the second pole piece as a mask to form a central notched structure. Since the second pole piece is precisely centered over the pedestal prior to notching, the pedestal is notched symmetrically to form a notched structure having side walls with angled slopes.

Abstract: A self aligned magnetoresistive sensor having a narrow and well defined track width and method of manufacture thereof.

Abstract: A magnetoresistive sensor having a well defined track width and method of manufacture thereof.

Abstract: The microcolumn configuration of the present invention provides for emission noise reduction through the use of a screened beam-limiting aperture for monitoring the electron beam current. This novel approach utilizes a screening aperture located between the emitter and the beam-limiting aperture, which screening aperture collects most of the current transmitted by the first lens of the electron beam column. In order to achieve good noise suppression, the screening aperture should let through only the portion of the beam where the electrons are correlated. The current collected by the beam-limiting aperture is then used as a reference signal in the image processing. The elimination of this noise increases the detection sensitivity of an inspection tool. This reduces the total number of required pixels and therefore increases the throughput of the tool.

Abstract: A method and system for electron beam lithography at high throughput with shorter electron beam column length, reduced electron-electron interactions, and higher beam current. The system includes a photocathode having a pattern composed of a periodic array of apertures with a specific geometry. The spacing of the apertures is chosen so as to maximize the transmission of the laser beam through apertures significantly smaller than the photon wavelength. The patterned photocathode is illuminated by an array of laser beams to allow blanking and gray-beam modulation of the individual beams at the source level by the switching of the individual laser beams in the array. Potential applications for this invention include electron beam direct write on wafers and mask patterning.

Abstract: A photocathode having a gate electrode so that modulation of the resulting electron beam is accomplished independently of the laser beam. The photocathode includes a transparent substrate, a photoemitter, and an electrically separate gate electrode surrounding an emission region of the photoemitter. The electron beam emission from the emission region is modulated by voltages supplied to the gate electrode. In addition, the gate electrode may have multiple segments that are capable of shaping the electron beam in response to voltages supplied individually to each of the multiple segments.

Abstract: A photocathode having a gate electrode so that modulation of the resulting electron beam is accomplished independently of the laser beam. The photocathode includes a transparent substrate, a photoemitter, and an electrically separate gate electrode surrounding an emission region of the photoemitter. The electron beam emission from the emission region is modulated by voltages supplied to the gate electrode. In addition, the gate electrode may have multiple segments that are capable of shaping the electron beam in response to voltages supplied individually to each of the multiple segments.

Abstract: A method and an accompanied apparatus for aligning an electron emitter with an extractor hole of a microcolumn. Four V-grooves, defined together with the window for forming the membrane and having bottoms situated on two axis are microfabricated on a chip. The axis intersect at a right angle and defines a center point for the extractor hole. The V-grooves are then used as references to align the electron emitter with the extractor hole, one axis at a time. The emitter is precisely aligned to the extractor hole because the extractor hole was formed with reference to the V-grooves. The thickness of the chip is used as the spacing reference between the emitter and the extractor.

Abstract: A field emission source produces a charged particle beam that can be electrostatically aligned with the optical axis. Quadrupole (or higher multipole) centering electrodes approximately centered on the optical axis are placed between the emitter and the extraction electrode. By applying centering potentials of equal amplitude and opposite polarity on opposing elements of the centering electrodes, an electrostatic deflection field is created near the optical axis. The electrostatic deflection field aligns the charged particle beam with the optical axis thereby obviating the need to mechanically align the emitter with the optical axis. A second set of centering electrodes may be used to deflect the charged particle beam back and to ensure that the charged particle beam is parallel with the optical axis. Further, the extraction electrode may be split into a quadrupole arrangement with the extraction and centering potentials superimposed.

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 photocathode having a gate electrode so that modulation of the resulting electron beam is accomplished independently of the laser beam. The photocathode includes a transparent substrate, a photoemitter, and an electrically separate gate electrode surrounding an emission region of the photoemitter. The electron beam emission from the emission region is modulated by voltages supplied to the gate electrode. In addition, the gate electrode may have multiple segments that are capable of shaping the electron beam in response to voltages supplied individually to each of the multiple segments.

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.

Abstract: A method and an accompanied apparatus for aligning an electron emitter with an extractor hole of a microcolumn. Four V-grooves, defined together with the window for forming the membrane and having bottoms situated on two axis are microfabricated on a chip. The axis intersect at a right angle and defines a center point for the extractor hole. The V-grooves are then used as references to align the electron emitter with the extractor hole, one axis at a time. The emitter is precisely aligned to the extractor hole because the extractor hole was formed with reference to the V-grooves. The thickness of the chip is used as the spacing reference between the emitter and the extractor.

Abstract: A method and system for cleaning the silicon microlenses in an electron-beam microcolumn in situ. The microlenses individually are heated by passing a current through each microlens. The current is utilized to heat the microlens to at least two hundred degrees Centigrade to prevent contamination and occasionally to a temperature on the order of six to seven hundred degrees Centigrade to remove any builtup or potential contamination.

Abstract: The present invention relates to chemically amplified resists and resist systems wherein some of the polar functional groups of the aqueous base soluble polymer or copolymers are protected with a cyclic aliphatic ketal protecting group such as methoxycyclohexanyl. The resists and the resist systems of the present invention containing the new protecting group have improved shelf-life and vacuum stability as compared to the prior art resists. Thus, the resists of the present invention are highly useful in e-beam lithographic applications.

Abstract: The present invention relates to chemically amplified resists and resist systems wherein some of the polar functional groups of the aqueous base soluble polymer or copolymers are protected with a cyclic aliphatic ketal protecting group such as methoxycyclohexanyl. The resists and the resist systems of the present invention containing the new protecting group have improved shelf-life and vacuum stability as compared to the prior art resists. Thus, the resists of the present invention are highly useful in e-beam lithographic applications.

Abstract: Quantum mechanical effect devices incorporate means for interrupting the two-dimensional carrier gas of a modulation doped structure to produce periodic potential variations which provide superlattice-like effects on current flowing nearby. The modulation doped structures incorporate specialized structures displaced from a current path which simultaneously confine the two-dimensional carrier gas into a quasi-one-dimensional carrier gas and subject the thus confined carrier gas and current flowing therein to superlattice-like effects by inducing periodic potential variations along the current path. The induced variations are produced by etching corrugations in the device edges or by forming them in biasing gates.