Focused ion beam imaging and process control

Claim 1

Ion beam machining apparatus comprising A. ion beam source means for directing a fine-focus ion beam onto an impingement site on a target for sputtering particles from the target, said ion beam defining an axis of incidence onto the target, said axis of incidence defining a Z-coordinate axis, B. electron source means for projecting a stream of electrons onto the target for neutralizing charge produced on the said ion beam relative to the target and maintain a selected sub-micron positional accuracy of said ion beam relative to the target, said electron source means having means for reducing emission of light energy, from said electron source means, which can impinge upon said photon detector means, C. photon detector means for detecting photons emitted in response to incidence of said ion beam on the target, and for generating photon detector signals representative of selected emission characteristics of said emitted photons, D. output means in electrical circuit with said photon detector means for detecting, in response to said photon detector signals, transitions between different material constituents within the target, and for identifying, in response to detected transitions between different material constituents within the target, a Z axis coordinate of the impingement site of said ion beam within the target, E. scanner means for selectively deflecting the position of the impingement site on the target, along a raster pattern, said raster pattern defining an X-Y plane substantially perpendicular to said Z axis, and F. means in electrical circuit with said scanner means for generating position signals representative of X-Y coordinates of the impingement site relative to said X-Y plane.

Claim 13

A method of applying an ion beam to etch a target, comprising A. directing a fine-focus ion beam onto an impingement site on a target for sputtering particles from the target, the ion beam defining an axis of incidence onto the target, said axis of incidence defining a Z-coordinate axis, B. utilizing an electron source to project a stream of electrons onto the target for neutralizing charge produced on the impingement site on the target by the ion beam, to stabilize said ion beam relative to the target and maintain a selected sub-micron positional accuracy of said ion beam relative to the target, C. utilizing a photon detector for detecting photons emitted in response to incidence of the ion beam on the target, D. reducing emission of light energy, from the electron source, which can impinge upon the photon detector, E. generating photon detector signals representative of selected emission characteristics of the emitted photons, F. detecting, in response to the photon detector signals, transitions between different material constituents within the target G. Identifying, in response to the step of detecting transitions between different material constituents within the target, a Z axis coordinate of the impingement site of said ion beam within the target, H. selectively deflecting the position of the impingement site on the target, along a raster pattern, the raster pattern defining an X-Y plane substantially perpendicular to said Z axis, and I. generating position signals representative of X-Y coordinates of the impingement site relative to said X-Y plane.

Claim 14

A method of applying an ion beam to etch a target, comprising A. directing a fine-focus ion beam onto an impingement site on a target for sputtering particles from the target, the ion beam defining an axis of incidence onto the target, said axis of incidence defining a Z-coordinate axis, B. utilizing an electron source to project a stream of electrons onto the target for neutralizing charge produced on the impingement site on the target by the ion beam, to stabilize said ion beam relative to the target and maintain a selected sub-micron positional accuracy of said ion beam relative to the target, C. utilizing a photon detector for detecting photons emitted in response to incidence of the ion beam on the target, D. reducing emission of light energy, from the electron source, which can impinge upon the photon detector, E. generating photon detector signals representative of selected emission characteristics of the emitted photons, F. detecting, in response to the photon detector signals, transitions between different material constituents within the target G. Identifying, in response to the step of detecting transitions between different material constituents within the target, a Z axis coordinate of the impingement site of said ion beam within the target, H. selectively deflecting the position of the impingement site on the target, along a raster pattern, the raster pattern defining an X-Y plane substantially perpendicular to said Z axis, and I. generating position signals representative of X-Y coordinates of the impingement site relative to said X-Y plane.