Abstract: A system is configured to perform metrology on a front surface, a back surface opposite the front surface, and/or an edge between the front surface and the back surface of a wafer. This can provide all wafer metrology and/or metrology of thin films on the back surface of the wafer. In an example, the thickness and/or optical properties of a thin film on a back surface of a wafer can be determined using a ratio of a greyscale image of a bright field light emerging from the back surface of the wafer under test to that of a reference wafer.

Abstract: Field curvature of an optical system is modified based on topography of the surface of a wafer such that an image of each of the segments of the surface is in focus across the segment. The wafer may be non-planar. The optical system may be a multi-element lens system connected to a controller that modifies the field curvature by changing position of the lens elements. The wafer may be held by a chuck, such as an edge grip chuck. Multiple optical systems may be arranged across a dimension of the wafer.

Abstract: This inspection system has an optical head, a support system, and a controller in electrical communication with the support system. The support system is configured to provide movement to the optical head with three degrees of freedom. The controller is programmed to control movement of the optical head using the support system such that the optical head maintains a constant angle of incidence relative to a wafer surface while imaging a circumferential edge of the wafer. An edge profiler may be scanned across the wafer to determine an edge profile. A trajectory of the optical head can be determined using the edge profile.

Abstract: Photoreflectance spectroscopy is used to measure strain at or near the edge of a wafer in a production process. The strain measurement is used to anticipate defects and make prospective corrections in later stages of the production process. Strain measurements are used to associate various production steps with defects to enhance later production processes.

Abstract: This semiconductor inspection and metrology system includes a knife-edge mirror configured to receive light reflected from a wafer. The knife-edge mirror is positioned at a focal point of the light reflected from the wafer such that the reflective film on the knife-edge mirror is configured to block at least some of the light reflected from the wafer. The portion of blocked light changes when the light reflected from the wafer is under-focused or over-focused. At least one sensor receives the light reflected from the wafer. Whether the light is under-focused or over-focused can be determined using a reading from the at least one sensor. A height of an illuminated region on the surface of the wafer can be determined using such a reading from the at least one sensor.

Abstract: This inspection system has an optical head, a support system, and a controller in electrical communication with the support system. The support system is configured to provide movement to the optical head with three degrees of freedom. The controller is programmed to control movement of the optical head using the support system such that the optical head maintains a constant angle of incidence relative to a wafer surface while imaging a circumferential edge of the wafer. An edge profiler may be scanned across the wafer to determine an edge profile. A trajectory of the optical head can be determined using the edge profile.

Abstract: Photoreflectance spectroscopy is used to measure strain at or near the edge of a wafer in a production process. The strain measurement is used to anticipate defects and make prospective corrections in later stages of the production process. Strain measurements are used to associate various production steps with defects to enhance later production processes.

Abstract: Field curvature of an optical system is modified based on topography of the surface of a wafer such that an image of each of the segments of the surface is in focus across the segment. The wafer may be non-planar. The optical system may be a multi-element lens system connected to a controller that modifies the field curvature by changing position of the lens elements. The wafer may be held by a chuck, such as an edge grip chuck. Multiple optical systems may be arranged across a dimension of the wafer.

Abstract: A tool for machining a workpiece, in particular a milling tool, is presented. Said tool comprises a shank which is drivable rotatably about a longitudinal axis and is fixable to a tool holding fixture. It further comprises a plate holding fixture that is arranged on one end of the shank, a support plate having at least one internal thread, a cutting element with at least one cutting edge, and at least one fastening element which is provided with an external thread that is adapted to the at least one internal thread.

Abstract: An ignition system for a rocket engine which improves the reliability of engine re-ignition by supplying additional oxygen to the ignitor directly from the rocket engines main fuel/oxygen injector elements, thereby eliminating the need for a supplemental oxygen supply system.