Abstract: A method for inspecting masks used to project patterns in photolithographic imaging comprises initially providing a photolithographic mask having a pattern field thereon, where in normal production use the pattern is transferred by a reduction projector as a demagnified pattern on a production substrate, and providing a movable field-defining aperture adjacent the mask, the aperture having a field area less than, and capable of defining a pattern subfield comprising only a portion of the entire photolithographic mask pattern field. The method then includes aligning the field-defining aperture with a pattern subfield comprising only a portion of the entire photolithographic mask pattern field. Using an energy source, the method includes projecting the pattern subfield onto a test substrate and exposing onto the test substrate the pattern subfield at a size between that normally exposed on a production substrate and the actual size of the pattern subfield on the photolithographic mask.

Abstract: A method and apparatus for controlling the thickness of a semiconductor wafer during a backside grinding process are disclosed. The present invention uses optical measurement of the wafer thickness during a backside grinding process to determine the endpoint of the grinding process. Preferred methods entail measuring light transmitted through or reflected by a semiconductor wafer as a function of angle of incidence or of wavelength. This information is then used, through the use of curve fitting techniques or formulas, to determine the thickness of the semiconductor wafer. Furthermore, the present invention may be used to determine if wedging of the semiconductor occurs and, if wedging does occur, to provide leveling information to the thinning apparatus such that a grinding surface can be adjusted to reduce or eliminate wedging.

Abstract: A method of reducing sound-induced vibrations in pellicles used in lithographic production of microelectronic features comprises providing a pellicle for protecting a photomask, monitoring background sound in the vicinity, or vibration, of the pellicle, providing opposing sound waves to the background sound, and causing the opposing sound waves to strike the pellicle to substantially cancel vibrations due to the background sound or vibration. When the background sound strikes the pellicle on one surface of the pellicle, the opposing sound waves may strike the pellicle on the opposing surface of the pellicle, and may be provided with substantially the same frequency and amplitude in the same phase to the background sound. Alternatively, opposing sound waves may strike the pellicle on the same surface of the pellicle as the background sound waves, may be provided with substantially the same frequency and amplitude in opposing phase to the background sound.

Abstract: A method of reducing sound-induced vibrations in pellicles used in lithographic production of microelectronic features comprises providing a pellicle for protecting a photomask, monitoring background sound in the vicinity, or vibration, of the pellicle, providing opposing sound waves to the background sound, and causing the opposing sound waves to strike the pellicle to substantially cancel vibrations due to the background sound or vibration. When the background sound strikes the pellicle on one surface of the pellicle, the opposing sound waves may strike the pellicle on the opposing surface of the pellicle, and may be provided with substantially the same frequency and amplitude in the same phase to the background sound. Alternatively, opposing sound waves may strike the pellicle on the same surface of the pellicle as the background sound waves, may be provided with substantially the same frequency and amplitude in opposing phase to the background sound.

Abstract: A method and apparatus for making phase shift masks are provided wherein an anti-reflective coating used on an opaque pattern layer of the mask fully covers the opaque pattern layer and has not been etched in the etching process to form the phase shift mask. A two-exposure method to form the phase shift mask is used wherein a photoresist having a defined dose-to-clear level is coated on the surface of the mask and the lower surface of the mask is exposed to a blanket exposure in an energy amount less than the dose-to-clear level. The open areas of the upper surface of the mask to be etched are exposed to an energy dose in an amount less than the dose-to-clear level, with the sum of the amounts of the lower surface energy and upper surface energy being at least the dose-to-clear level. The method and apparatus minimizes and/or avoids etching of the anti-reflective coating.

Abstract: A method for inspecting masks used to project patterns in photolithographic imaging comprises initially providing a photolithographic mask having a pattern field thereon, where in normal production use the pattern is transferred by a reduction projector as a demagnified pattern on a production substrate, and providing a movable field-defining aperture adjacent the mask, the aperture having a field area less than, and capable of defining a pattern subfield comprising only a portion of the entire photolithographic mask pattern field. The method then includes aligning the field-defining aperture with a pattern subfield comprising only a portion of the entire photolithographic mask pattern field. Using an energy source, the method includes projecting the pattern subfield onto a test substrate and exposing onto the test substrate the pattern subfield at a size between that normally exposed on a production substrate and the actual size of the pattern subfield on the photolithographic mask.

Abstract: The invention provides systems and a method for reducing pellicle distortion. One feature of the invention reduces distortion of a pellicle by providing an airtight mounting structure for coupling a pellicle to a mask; and a port on the mounting structure though which a pressure difference can be created between the interior portion and an exterior environment. Hence, distortion can be reduced by controlling the pressure in the interior portion between the pellicle, the pellicle mounting structure and the mask. Another feature places an aerodynamic fairing adjacent the mask to reduce aerodynamic drag and, hence, suppress turbulent air flow over the pellicle. The features can be used separately or in combination.

Abstract: The invention provides systems and a method for reducing pellicle distortion. One feature of the invention reduces distortion of a pellicle by providing an airtight mounting structure for coupling a pellicle to a mask; and a port on the mounting structure though which a pressure difference can be created between the interior portion and an exterior environment. Hence, distortion can be reduced by controlling the pressure in the interior portion between the pellicle, the pellicle mounting structure and the mask. Another feature places an aerodynamic fairing adjacent the mask to reduce aerodynamic drag and, hence, suppress turbulent air flow over the pellicle. The features can be used separately or in combination.

Abstract: A method and apparatus for making phase shift masks are provided wherein an anti-reflective coating used on an opaque pattern layer of the mask fully covers the opaque pattern layer and has not been etched in the etching process to form the phase shift mask. A two-exposure method to form the phase shift mask is used wherein a photoresist having a defined dose-to-clear level is coated on the surface of the mask and the lower surface of the mask is exposed to a blanket exposure in an energy amount less than the dose-to-clear level. The open areas of the upper surface of the mask to be etched are exposed to an energy dose in an amount less than the dose-to-clear level, with the sum of the amounts of the lower surface energy and upper surface energy being at least the dose-to-clear level. The method and apparatus minimizes and/or avoids etching of the anti-reflective coating.

Abstract: An assist feature is formed on a lithographic reticle or mask using a hybrid resist and an exposure dose such that only an annular area is effectively exposed having a width that is potentially less than the minimum feature size that can be resolved by the mask exposure tool to simultaneously or sequentially form both a feature of interest and an assist feature for enhancing imaging of the feature of interest when the feature is printed to a wafer. Since the assist feature can be imaged simultaneously with the feature of interest or multiple assist features imaged concurrently, possibly between closely spaced features, data volume and mask writing time are greatly reduced. The invention is particularly applicable to the scaling of contact holes for connections to active devices in extremely high density integrated circuits.

Abstract: An automated system for analyzing mask defects in a semiconductor manufacturing process is presented. This system combines results from an inspection tool and design layout data from a design data repository corresponding to each mask layer being inspected with a computer program and a predetermined rule set to determine when a defect on a given mask layer has occurred. Mask inspection results include the presence, location and type (clear or opaque) of defects. Ultimately, a determination is made as to whether to scrap, repair or accept a given mask based on whether the defect would be likely to cause product failure. Application of the defect inspection data to the design layout data for each mask layer being inspected prevents otherwise acceptable wafer masks from being scrapped when the identified defects are not in critical areas of the mask.

Abstract: The invention provides systems and a method for reducing pellicle distortion. One feature of the invention reduces distortion of a pellicle by providing an airtight mounting structure for coupling a pellicle to a mask; and a port on the mounting structure though which a pressure difference can be created between the interior portion and an exterior environment. Hence, distortion can be reduced by controlling the pressure in the interior portion between the pellicle, the pellicle mounting structure and the mask. Another feature places an aerodynamic fairing adjacent the mask to reduce aerodynamic drag and, hence, suppress turbulent air flow over the pellicle. The features can be used separately or in combination.

Abstract: The current invention performs short pulse laser ablation of clear defect regions on a mask prior to patching the clear defect regions. The short-pulse laser ablation removes any residue that absorbs light. Thus, the ablation completely cleans the surface of the clear defect regions, meaning that any patches of the surface will better adhere to the surface of the mask. This is particularly important during those situations where a later etch of a conductive surface added to the mask creates a solvent because the etchant interacts with residue on the mask, and wherein the solvent attacks the patch material at the patch material's interface.

Abstract: An assist feature is formed on a lithographic reticle or mask using a hybrid resist and an exposure dose such that only an annular area is effectively exposed having a width that is potentially less than the minimum feature size that can be resolved by the mask exposure tool to simultaneously or sequentially form both a feature of interest and an assist feature for enhancing imaging of the feature of interest when the feature is printed to a wafer. Since the assist feature can be imaged simultaneously with the feature of interest or multiple assist features imaged concurrently, possibly between closely spaced features, data volume and mask writing time are greatly reduced. The invention is particularly applicable to the scaling of contact holes for connections to active devices in extremely high density integrated circuits.

Abstract: A method and apparatus for controlling the thickness of a semiconductor wafer during a backside grinding process are disclosed. The present invention uses optical measurement of the wafer thickness during a backside grinding process to determine the endpoint of the grinding process. Preferred methods entail measuring light transmitted through or reflected by a semiconductor wafer as a function of angle of incidence or of wavelength. This information is then used, through the use of curve fitting techniques or formulas, to determine the thickness of the semiconductor wafer. Furthermore, the present invention may be used to determine if wedging of the semiconductor occurs and, if wedging does occur, to provide leveling information to the thinning apparatus such that a grinding surface can be adjusted to reduce or eliminate wedging.

Abstract: A method and apparatus for controlling the thickness of a semiconductor wafer during a backside grinding process are disclosed. The present invention uses optical measurement of the wafer thickness during a backside grinding process to determine the endpoint of the grinding process. Preferred methods entail measuring light transmitted through or reflected by a semiconductor wafer as a function of angle of incidence or of wavelength. This information is then used, through the use of curve fitting techniques or formulas, to determine the thickness of the semiconductor wafer. Furthermore, the present invention may be used to determine if wedging of the semiconductor occurs and, if wedging does occur, to provide leveling information to the thinning apparatus such that a grinding surface can be adjusted to reduce or eliminate wedging.

Abstract: A method of variably exposing photosensitive material. A semiconductor wafer is provided. A first target region and a second target region are identified on the semiconductor wafer. Photosensitive material is provided on the semiconductor wafer. An illuminating system including a source of illumination is provided. A mask is provided between the source of illumination and the photosensitive material. The photosensitive material is illuminated through the mask with the illuminating system to provide in a single step of the illuminating system a first illumination dose to the first target region and a second illumination dose to the second target region. The first illumination dose differs from the second illumination dose. No further illumination dose is provided to equalize the first illumination dose and the second illumination dose.

Abstract: A method of repairing defects on masks includes the step of providing a coating on the mask to prevent damage to clear regions of the mask from laser ablation splatter, laser ablation caused quartz pitting, laser deposition staining, and FIB caused gallium staining. The coating is a metal, a polymer, or a carbon material. The coating is formed on clear regions of the mask as well as either over or under the light absorbing material of the mask. A coating comprising a thin copper layer significantly improves imaging with the ion beam while protecting clear regions of the mask from FIB stain. A coating formed of a photosensitive polymer is used to etch opaque defects. While wanted opaque regions adjacent an opaque defect are also etched in this etch step, these created clear defects are then repaired in a subsequent FIB deposition step while a copper coating protects adjacent clear regions from FIB stain.

Abstract: A method of repairing defects on masks includes the step of providing a coating on the mask to prevent damage to clear regions of the mask from laser ablation splatter, laser ablation caused quartz pitting, laser deposition staining, and FIB caused gallium staining. The coating is a metal, a polymer, or a carbon material. The coating is formed on clear regions of the mask as well as either over or under the light absorbing material of the mask. A coating comprising a thin copper layer significantly improves imaging with the ion beam while protecting clear regions of the mask from FIB stain. A coating formed of a photosensitive polymer is used to etch opaque defects. While wanted opaque regions adjacent an opaque defect are also etched in this etch step, these created clear defects are then repaired in a subsequent FIB deposition step while a copper coating protects adjacent clear regions from FIB stain.

Abstract: A method of repairing defects on masks includes the step of providing a coating on the mask to prevent damage to clear regions of the mask from laser ablation splatter, laser ablation caused quartz pitting, laser deposition staining, and FIB caused gallium staining. The coating is a metal, a polymer, or a carbon material. The coating is formed on clear regions of the mask as well as either over or under the light absorbing material of the mask. A coating comprising a thin copper layer significantly improves imaging with the ion beam while protecting clear regions of the mask from FIB stain. A coating formed of a photosensitive polymer is used to etch opaque defects. While wanted opaque regions adjacent an opaque defect are also etched in this etch step, these created clear defects are then repaired in a subsequent FIB deposition step while a copper coating protects adjacent clear regions from FIB stain.