Abstract: Methods and apparatus to facilitate the measurement of the amount of scattered electrons collected by an anti-fogging baffle arrangement are provided. For some embodiments, by affixing a lead to an electrically isolated (floating) portion of the baffle arrangement, the amount of scattered electrons collected thereby may be read out, for example, as a current signal. Thus, for such embodiments, the baffle arrangement may double as a detector, allowing an image of surface (e.g., a mask or substrate surface) to be generated.

Abstract: Embodiments of the present invention may be utilized to improve electron beam deflection. One embodiment provides an electrostatic deflection system with electrodes that minimize aberrations and to achieve vertical incidence simultaneously. By using at least two stages of deflection for a deflection direction, the present invention allows the deflected electron beam to pass a back focal plane of an objective lens while deflection capacitors are not disposed across the back focal plane. As a result, deflection electrodes can have an angle of 120° to minimize aberrations and simultaneously achieve vertical incidence of the electron beam on a target to avoid distortions or changes in magnification with height variations of the target or focus variations.

Abstract: Methods and apparatus to facilitate the measurement of the amount of scattered electrons collected by an anti-fogging baffle arrangement are provided. For some embodiments, by affixing a lead to an electrically isolated (floating) portion of the baffle arrangement, the amount of scattered electrons collected thereby may be read out, for example, as a current signal. Thus, for such embodiments, the baffle arrangement may double as a detector, allowing an image of surface (e.g., a mask or substrate surface) to be generated.

Abstract: An apparatus and method for deflecting electron beams with high precision and high throughput. At least one electrode of a deflecting capacitor is connected to a signal source via a coaxial cable. A termination resistor is further connected to the coaxial cable and the electrode at the joint of the coaxial cable and the electrode. The termination resistor has a resistance matched to the impedance of the coaxial cable and the electrode has an impedance matched to half of the impedance of the coaxial. The deflecting capacitors of the present invention have a minimized loss of precision due to eddy current. The spacing of electrodes in the deflecting capacitors is reduced by a factor of approximately two compared to the state-the-art system.

Abstract: An electron beam column comprises a thermal field emission electron source to generate an electron beam, an electron beam blanker, a beam shaping module, and electron beam optics comprising a plurality of electron beam lenses. In one version, the optical parameters of the electron beam blanker, beam shaping module, and electron beam optics are set to achieve an acceptance semi-angle ? of from about ¼ to about 3 mrads, where the acceptance semi-angle ? is the half the angle subtended by the electron beam at the writing plane. The beam-shaping module can also operate as a single lens using upper and lower projection lenses. A multifunction module for an electron beam column is also described.

Abstract: Embodiments of the present invention may be utilized to improve electron beam deflection. One embodiment provides an electrostatic deflection system with electrodes that minimize aberrations and to achieve vertical incidence simultaneously. By using at least two stages of deflection for a deflection direction, the present invention allows the deflected electron beam to pass a back focal plane of an objective lens while deflection capacitors are not disposed across the back focal plane. As a result, deflection electrodes can have an angle of 120° to minimize aberrations and simultaneously achieve vertical incidence of the electron beam on a target to avoid distortions or changes in magnification with height variations of the target or focus variations.

Abstract: An apparatus and method for deflecting electron beams with high precision and high throughput. At least one electrode of a deflecting capacitor is connected to a signal source via a coaxial cable. A termination resistor is further connected to the coaxial cable and the electrode at the joint of the coaxial cable and the electrode. The termination resistor has a resistance matched to the impedance of the coaxial cable and the electrode has an impedance matched to half of the impedance of the coaxial. The deflecting capacitors of the present invention have a minimized loss of precision due to eddy current. The spacing of electrodes in the deflecting capacitors is reduced by a factor of approximately two compared to the state-the-art system.

Abstract: A backscattered electron detector capable of detecting electrons backscattered from a substrate includes a p-n junction diode having a p-doped semiconductor in contact with an n-doped semiconductor and a surface to receive the backscattered electrons. The backscattered electron detector also has a diode voltage source adapted to electrically bias the diode relative to the substrate by a diode bias voltage of at least about 500 V to increase the number or energy level of the backscattered electrons received by the diode. A signal amplifier may be used to process an input signal from the diode and generate an output signal that is amplified and passed to a controller that uses the amplified signal to locate a fiducial mark on the substrate.

Abstract: A method and apparatus for a charged particle scanning system and an automatic inspection system, including wafers and masks used in microcircuit fabrication. A charged particle beam is directed at the surface of a substrate for scanning that substrate and a selection of detectors are included to detect at least one of the secondary charged particles, back-scattered charged particles and transmitted charged particles from the substrate. The substrate is mounted on an x-y stage to provide at least one degree of freedom while the substrate is being scanned by the charged particle beam. The substrate is also subjected to an electric field on it's surface to accelerate the secondary charged particles. The system facilitates inspection at low beam energies on charge sensitive insulating substrates and has the capability to accurately measure the position of the substrate with respect to the charged particle beam.

Abstract: There is disclosed numerous embodiments of a method and apparatus for a particle scanning system and an automatic inspection system. In each of these a particle beam is directed at the surface of a substrate for scanning that substrate. Also included are a selection of detectors to detect at least one of the secondary particles, back-scattered particles and transmitted particles from the substrate. The substrate is mounted on an x-y stage to provide it with at least one degree of freedom while the substrate is being scanned by the/particle beam. The substrate is also subjected to an electric field on it's surface to accelerate the secondary particles. The system also has the capability to accurately measure the position of the substrate with respect to the charged particle beam. Additionally, there is an optical alignment means for initially aligning the substrate beneath the,particle beam means.