Abstract: A compact detector for secondary and backscattered electrons in a scanning electron beam system includes a microchannel plate detector and a solid state detector connected in a tandem manner. The detector offers large bandwidth and high dynamic range. The detector can be used for article inspection, lithography, metrology, and other related applications. The compactness of the detector makes it ideally suited for utilization in a miniature electron beam column, such as a microcolumn.

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 compact detector for secondary and backscattered electrons in a scanning electron beam system includes a microchannel plate detector and a solid state detector connected in a tandem manner. The detector offers large bandwidth and high dynamic range. The detector can be used for article inspection, lithography, metrology, and other related applications. The compactness of the detector makes it ideally suited for utilization in a miniature electron beam column, such as a microcolumn.

Abstract: A photocathode emitter as a source of electron beams, having an optically transmissive substrate patterned to define a protrusion, heat conducting material occupying the space surrounding the protrusion, and a photoemitter layer over the protrusion. The photoemitter is positioned on the side of the substrate opposite the surface on which the illumination is incident, and has an irradiation region at the contact with the top of the protrusion patterned on the substrate, and an emission region opposite the irradiation region, these regions being defined by the path of the illumination. The heat conducting material around the protrusion conducts heat away from this focused region of illumination on the photocathode to allow higher currents to be achieved from the photocathode and thus permits higher throughput rates in applications including electron beam lithography. In one version, the photocathode is fabricated using microfabrication techniques, to achieve a small emission spot size.

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 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: In electron beam lithography, a lithography system uses multiple microcolumns in an array to increase throughput for direct writing of semiconductor wafers. The mismatch between the microcolumn array and the semiconductor die periodicity is resolved by using only one microcolumn to scan each individual die. This is accomplished by assuring that the stage carrying the semiconductor wafer moves a total distance in each of the X and Y directions which is greater than the pitch between adjacent die. Hence each die is scanned by only a single microcolumn although at possibly different times during the total stage motion.

Abstract: For electron beam wafer or mask processing, a registration mark is capacitively coupled to the top surface of an overlying resist layer on a substrate to form a voltage potential on the surface of the resist layer directly over the registration mark. The registration mark is directly connected to an electrical lead that produces an AC voltage on the registration mark, which is capacitively induced on the surface of the resist layer. Alternatively, the registration mark itself is capacitively coupled to a conductive plate placed on the bottom surface of the semiconductor substrate. An AC voltage is then applied to the conductive plate that induces a charge on the registration mark, which then capacitively induces a charge on the surface of the layer of resist. An electron beam scanning across the surface of the resist layer generates secondary electrons. The secondary electrons have a low energy and are affected by the voltage potential created at the surface of the resist layer.

Abstract: For electron beam wafer or mask processing, a registration mark is capacitively coupled to the top surface of an overlying resist layer on a substrate to form a voltage potential on the surface of the resist layer directly over the registration mark. The registration mark is directly connected to an electrical lead that produces an AC voltage on the registration mark, which is capacitively induced on the surface of the resist layer. Alternatively, the registration mark itself is capacitively coupled to a conductive plate placed on the bottom surface of the semiconductor substrate. An AC voltage is then applied to the conductive plate that induces a charge on the registration mark, which then capacitively induces a charge on the surface of the layer of resist. An electron beam scanning across the surface of the resist layer generates secondary electrons. The secondary electrons have a low energy and are affected by the voltage potential created at the surface of the resist layer.

Abstract: A method for electron beam writing of microcircuit patterns utilizing the combination of spiral scan techniques and variable beam sizes. The circuit patterns are outlined in a spiral scan motion using a small size beam in order to ensure good edge sharpness and accuracy. The beam is then increased in size to fill-in the inside area of the pattern. Increasing the beam size increases the beam current and, correspondingly, the exposure speed and system throughput.