Abstract: Methods and apparatus for controlling illumination uniformity by altering the size of a slit are disclosed. According to one aspect of the present invention, an apparatus includes a light source, an exposure surface, and an illumination unit. The light source generates a beam that is projected onto the exposure surface. The illumination arrangement includes a first support surface and a first removable plate that is configured to be coupled to the first support surface. A first edge of the first removable plate and a second edge cooperate to at least partially define a slit through which the beam is projected.

Abstract: Methods and apparatus for substantially continuously measuring the surface of a wafer during a polishing process are disclosed. According to one aspect of the present invention, an apparatus includes a wafer support table that supports a wafer, a polishing pad that polishes a surface of the wafer, and a polishing pad structure that rotates the polishing pad over the surface of the wafer. The apparatus also includes a measuring device which is capable of continuously measuring the surface of the wafer during polishing of the surface of the wafer.

Abstract: A system and method of calculating estimated image profiles. The system and method includes providing lens characteristic data and performing simulation calculations for various levels of aberration components using the lens characteristic data. A response surface functional relation is built between selected variables of the lens characteristics, in particular the lens aberration components, and the Image Profile using the simulation calculations. Evaluation is then performed on the arbitrary specified aberration values of a lens in relation to the response surface functional relations to provide a calculated estimate of the Image Profile for the specified aberration values. A machine readable medium and exposure apparatus are also provided.

Abstract: Methods for using critical dimension test marks (test marks) for the rapid determination of the best focus position of lithographic processing equipment and critical dimension measurement analysis across a wafer's surface are described. In a first embodiment, a plurality of test mark arrays are distributed across the surface of a wafer, a different plurality being created at a plurality of focus positions. Measurement of the length or area of the resultant test marks allows for the determination of the best focus position of the processing equipment. Critical dimension measurements at multiple points on a wafer with test marks allow for the determination of process accuracy and repeatability and further allows for the real-time detection of process degradation. Using test marks which require only a relatively simple optical scanner and sensor to measure their length or area, it is possible to measure hundreds of measurement values across a wafer in thirty minutes.

Abstract: A test mark, as well as methods for forming and using the test mark to facilitate the measurement of the critical dimensions of etched features in semiconductor and other wafer level processing is described. The test marks may be used to characterize, calibrate and/or monitor etch performance. Test marks are defined by imaging (typically at partial exposures) overlapping, angularly offset lines in a resist that covers a layer to be etched. The lines preferably have line widths that are equal (or related) to a critical dimension of interest. After the resist is developed and otherwise processed, the layer is etched as appropriate, thereby creating the test marks. The test marks are then imaged to facilitate the determination of a geometric parameter of each mark. Most commonly, the geometric parameter determined relates to the area of the mark and/or the length of its major dimension.

Abstract: A method for diagnosing a lithographic tool. The method includes developing digitalized images of at least one wafer pattern with different exposure doses and assembling the digitized images into a pupilgram. The at least one function is of a known illuminator behavior of the lithographic tool is modeled. The pupilgram is fitted to the modeled function to determine whether a behavior associated with the pupilgram is within predetermined limits of illuminator behavior to diagnosis imperfections in the illuminator behavior. One technique applied to the illuminator analysis consists of evaluating the dose transmitted (by direct calculation) by the lens for a given input pupilgram (or set of pupilgram basis functions), a given pattern size and pitch, and a defined lens NA, is described.

Abstract: Methods and apparatus for enabling both isolated and dense patterns to be accurately patterned onto a wafer are disclosed. According to one aspect of the present invention, an illumination system that is suitable for use as a part of a projection tool includes an illumination source and an illuminator aperture. The illuminator aperture has a center point and an outer edge, and also includes a first pole and a second pole. The first pole is defined substantially about the center point, and the second pole is defined substantially between the first pole and the outer edge of the first pole. The illumination source is arranged to provide a beam to the illuminator aperture.

Abstract: Methods and apparatus for enabling both isolated and dense patterns to be accurately patterned onto a wafer are disclosed. According to one aspect of the present invention, an illumination system that is suitable for use as a part of a projection tool includes an illumination source and an illuminator aperture. The illuminator aperture has a center point and an outer edge, and also includes a first pole and a second pole. The first pole is defined substantially about the center point, and the second pole is defined substantially between the first pole and the outer edge of the first pole. The illumination source is arranged to provide a beam to the illuminator aperture.

Abstract: Apparatus for performing measurement of a dimension of a test marked formed by overlapping feature imaged onto a an image forming layer of a semiconductor wafer and the calculation of the critical dimensions of the features from test mark. This is used in semiconductor processing. Also included is software configured to program a measurement device to perform the measurement and calculation of the dimension of a test mark.

Abstract: Variation in position of test marks formed of overlapping exposed features imaged by an imaging structure such as that of a lithography tool are characterized at high speed and with extremely high accuracy by imaging test marks formed in resist or on a target or wafer by a lithographic process, collecting irradiance distribution data and fitting a mathematical function to respective portions or regions of output data corresponding to a test mark of a test mark pattern such as respective maxima or minima regions or other regions of the irradiance distribution data to determine actual location and shift of position of respective patterns of test marks. Metrology fields are formed of patterns of test marks on test wafers or production wafers preferably including a critical dimension exposed at different focus distances and/or illumination conditions to capture position/aberration data for the imaging structure.

Abstract: Methods for using critical dimension test marks (test marks) for the rapid determination of the best focus position of lithographic processing equipment and critical dimension measurement analysis across a wafer's surface are described. In a first embodiment, a plurality of test mark arrays are distributed across the surface of a wafer, a different plurality being created at a plurality of focus positions. Measurement of the length or area of the resultant test marks allows for the determination of the best focus position of the processing equipment. Critical dimension measurements at multiple points on a wafer with test marks allow for the determination of process accuracy and repeatability and further allows for the real-time detection of process degradation. Using test marks which require only a relatively simple optical scanner and sensor to measure their length or area, it is possible to measure hundreds of measurement values across a wafer in thirty minutes.

Abstract: Increased accuracy of measurement of variation of a critical dimension is achieved through measurement of area of a test mark by detection of intensity of radiation such as broadband light with which at least a portion of a test mark is imaged. The test mark is preferably formed by partial lithographic exposures of overlapping features, preferably lines having a width approximating a critical dimension of interest and at a shallow angle to each other such that the test mark has the shape of a parallelogram or rhombus.

Abstract: A retention system for securing a stage mirror to the wafer stage of a semiconductor manufacturing device includes at least one first bracket and at least one second bracket. The retention system rigidly secures the stage mirror to the wafer stage during movement of the wafer stage to reduce positional measurement errors. The at least one first bracket has a substantially planar first contact surface for engaging the reflective surface of the mirror. The first contact surface is a finished aluminum surface, which does not scratch the mirror surface. The at least one first bracket is formed with a gusset providing increased stiffness in the direction of movement of the wafer stage. The at least one second bracket includes an actuator for moving a substantially planar second contact surface into engagement with a rear surface of the mirror. In one embodiment, the actuator is a threaded fastener and the second contact surface is a finished polyimide resin tip.

Abstract: A test mark, as well as methods for forming and using the test mark to facilitate the measurement of the critical dimensions of etched features in semiconductor and other wafer level processing is described. The test marks may be used to characterize, calibrate and/or monitor etch performance. Test marks are defined by imaging (typically at partial exposures) overlapping, angularly offset lines in a resist that covers a layer to be etched. The lines preferably have line widths that are equal (or related) to a critical dimension of interest. After the resist is developed and otherwise processed, the layer is etched as appropriate, thereby creating the test marks. The test marks are then imaged to facilitate the determination of a geometric parameter of each mark. Most commonly, the geometric parameter determined relates to the area of the mark and/or the length of its major dimension.

Abstract: A retention system for securing a stage mirror to the wafer stage of a semiconductor manufacturing device includes at least one first bracket and at least one second bracket. The retention system rigidly secures the stage mirror to the wafer stage during movement of the wafer stage to reduce positional measurement errors. The at least one first bracket has a substantially planar first contact surface for engaging the reflective surface of the mirror. The first contact surface is a finished aluminum surface, which does not scratch the mirror surface. The at least one first bracket is formed with a gusset providing increased stiffness in the direction of movement of the wafer stage. The at least one second bracket includes an actuator for moving a substantially planar second contact surface into engagement with a rear surface of the mirror. In one embodiment, the actuator is a threaded fastener and the second contact surface is a finished polyimide resin tip.

Abstract: A method for forming a critical dimension test mark, and the use of the mark to characterize and monitor imaging performance is provided. Methods in accordance with the present invention encompass an exposure of an essentially standard critical dimension bar at each of two overlapping orientations that are rotated about an axis with respect to each other. The overlapped portion forming a critical dimension test mark that is useful for enabling low cost, rapid determination of sub-micron critical dimensions for characterizing exposure tool imaging performance and in-process performance monitoring using optical measurement systems.

Abstract: A method of characterizing photolithographic tool performance is presented. Variations in performance over an image or exposure field are evaluated and contributions to the variation due to the partial coherence factor of the tool separated from other contributing factors. Methods of determining the relative magnitude of these variations is provided and a photolithographic tool that incorporates these methods described.

Abstract: Improvements in a focusing apparatus having an objective optical system for optically manufacturing a workpiece, forming a desired pattern on a surface of a workpiece or inspecting a pattern on a workpiece and used to adjust the state of focusing between the surface of the workpiece and the objective optical system. The focusing apparatus has a first detection system having a detection area at a first position located outside the field of the objective optical system, a second detection system having a detection area at a second position located outside the field of the objective optical system and spaced apart from the first position, and a third detection system having a detection area at a third position located outside the field of the objective optical system and spaced apart from each of the first and second positions.

Abstract: A method for forming a critical dimension test mark, and the use of the mark to characterize and monitor imaging performance is provided. Methods in accordance with the present invention encompass an exposure of an essentially standard critical dimension bar at each of two overlapping orientations that are rotated about an axis with respect to each other. The overlapped portion forming a critical dimension test mark that is useful for enabling low cost, rapid determination of sub-micron critical dimensions for characterizing exposure tool imaging performance and in-process performance monitoring using optical measurement systems.

Abstract: A method and apparatus to analyze the aerial image of an optical system using a subwavelength slit. A slit configuration yields a higher signal-to-noise ratio than that achievable with a round aperture. The slit also allows the polarization of the aerial image to be analyzed. In an alternative embodiment a tunneling slit is used. The tunneling slit comprises an optically transparent ridge-like structure mounted to a substrate, the combined structure covered by a thin, planar metal film.