Abstract: A system and method for reducing peak power of a laser pulse and reducing speckle contrast of a single pulse comprises a plurality of beamsplitters, mirrors and delay elements oriented to split and delay a pulse or pulses transmitted from a light emitting device. The design provides the ability to readily divide the pulse into multiple pulses by delaying the components relative to one another. Reduction of speckle contrast entails using the same or similar components to the power reduction design, reoriented to orient received energy such that the angles between the optical paths are altered such that the split or divided light energy components strike the target at different angles or different positions. An alternate embodiment for reducing speckle contrast is disclosed wherein a single pulse is passed in an angular orientation through a grating to create a delayed portion of the pulse relative to the leading edge of the pulse.

Abstract: A method and apparatus for simultaneous high-speed inspection and acquisition of multiple data channels is provided. The method and apparatus enables inspecting semiconductor wafers and reticles and comprises converting a single image region into two image sections, reorienting one image into a transposed configuration enabling simultaneous scanning of two inspected object locations with a single sensor, and controlling acquisition parameters for a second image by using information collected from a first image in a feedback arrangement. The design provides a dual-linear or time-delay-integration sensor operating in a split readout configuration mode to simultaneously provide data from two regions of the sensor using two sets of readout circuitry.

Abstract: A system and method for inspecting a specimen, such as a semiconductor wafer, including illuminating at least a portion of the specimen using an excimer source using at least one relatively intense wavelength from the source, detecting radiation received from the illuminated portion of the specimen, analyzing the detected radiation for potential defects present in the specimen portion.

Abstract: A method and apparatus for propagating charge through a sensor and implementation thereof is provided. The method and apparatus may be used to inspect specimens, the sensor operating to advance an accumulated charge between gates of the TDI sensor. The design implementation provides a set of values representing a plurality of out of phase signals, such as sinusoidal or trapezoidal signals. These out of phase signals are converted and transmitted to the sensor. The converted signals cause the sensor to transfer charges in the sensor toward an end of the sensor. Aspects such as feed through correction and correction of nonlinearities are addressed.

Abstract: A system and method for reducing peak power of a laser pulse and reducing speckle contrast of a single pulse comprises a plurality of elements oriented to split and delay a pulse or pulses transmitted from a light emitting device. The design provides the ability to divide the pulse into multiple pulses by delaying the components relative to one another. Reduction of speckle contrast entails using the same or similar components to the power reduction design, reoriented to orient received energy wherein angles between the optical paths are altered such that the split or divided light energy components strike the target at different angles or different positions. An alternate embodiment for reducing speckle contrast is disclosed wherein a single pulse is passed in an angular orientation through a grating to create a delayed portion of the pulse relative to the leading edge of the pulse.

Abstract: A reduced size catadioptric objective and system is disclosed. The objective may be employed with light energy having a wavelength in the range of approximately 190 nanometers through the infrared light range. Elements are less than 100 mm in diameter. The objective comprises a focusing lens group configured to receive the light energy and comprising at least one focusing lens. The objective further comprises at least one field lens oriented to receive focused light energy from the focusing lens group and provide intermediate light energy. The objective also includes a Mangin mirror arrangement positioned to receive the intermediate light energy from the field lens and form controlled light energy for transmission to a specimen. The Mangin mirror arrangement imparts controlled light energy with a numerical aperture in excess of 0.65 and up to approximately 0.90, and the design may be employed in various environments.

Abstract: A reduced size catadioptric objective and system is disclosed. The objective may be employed with light energy having a wavelength in the range of approximately 190 nanometers through the infrared light range. Elements are less than 100 mm in diameter. The objective comprises a focusing lens group configured to receive the light energy and comprising at least one focusing lens. The objective further comprises at least one field lens oriented to receive focused light energy from the focusing lens group and provide intermediate light energy. The objective also includes a Mangin mirror arrangement positioned to receive the intermediate light energy from the field lens and form controlled light energy for transmission to a specimen. The Mangin mirror arrangement imparts controlled light energy with a numerical aperture in excess of 0.65 and up to approximately 0.90, and the design may be employed in various environments.

Abstract: A method and apparatus for inspecting a specimen are provided. The apparatus comprises a primary illumination source, a catadioptric objective exhibiting central obscuration that directs light energy received from the primary illumination source at a substantially normal angle toward the specimen, and an optical device, such as a prism or reflective surface, positioned within the central obscuration resulting from the catadioptric objective for receiving further illumination from a secondary illumination source and diverting the further illumination to the specimen. The method comprises illuminating a surface of the specimen at a variety of angles using a primary illumination source, illuminating the surface using a secondary illumination source, the illuminating by the secondary illumination source occurring at a substantially normal angle of incidence; and imaging all reflected, scattered, and diffracted light energy received from the surface onto a detector.

Abstract: A system for multiple mode imaging is disclosed herein. The system is a catadioptric system preferably having an NA greater than 0.9, highly corrected for low and high order monochromatic aberrations. This system uses unique illumination entrances and can collect reflected, diffracted, and scattered light over a range of angles. The system includes a catadioptric group, focusing optics group, and tube lens group. The catadioptric group includes a focusing mirror and a refractive lens/mirror element. The focusing optics group is proximate to an intermediate image, and corrects for aberrations from the catadioptric group, especially high order spherical aberration and coma. The tube lens group forms the magnified image. Different tube lens groups can be used to obtain different magnifications, such as a varifocal tube lens group to continuously change magnifications from 20 to 200×. Multiple imaging modes are possible by varying the illumination geometry and apertures at the pupil plane.

Abstract: A variable modulated transfer function (MTF) design employing a variable gate voltage source for use in inspecting specimens is disclosed. The design applies a variable gate voltage to each pixel of a sensor, wherein applying the variable gate voltage to each pixel adjusts the MTF of the pixel. MTF adjustment improves adverse effects encountered during inspection, such as aliasing and maintaining contrast.

Abstract: A system and method for inspecting a multi-layer sample, such as a silicon wafer, is disclosed. The design reduces variations in total reflected energy due to thin film interference. The design includes illuminating the sample at two incident angle ranges, where the two incident angle ranges are such that variation in total reflected energy at a first incident angle range may be employed to balance variation in total reflected energy at a second incident angle range. Defects are detected using die-to-die subtraction of the sample illuminated at the two incident angle ranges.

Abstract: A system and method for inspection is disclosed. The design generally employs as many as four design principles, including employing at least one lens from a relatively low dispersion glass, at least one additional lens from an additional material different from the relatively low dispersion glass, generally matching the relatively low dispersion properties of the relatively low dispersion glass. The design also may include at least one further lens from a further material different from and exhibiting a significantly different dispersion power from the relatively low dispersion glass and the additional material. Finally, the design may include lenses positioned to insert a significant amount of color within the objective, a gap, and additional lenses, the gap and additional lenses serving to cancel the color inserted.

Abstract: A system and method for inspecting a specimen, such as a semiconductor wafer, including illuminating at least a portion of the specimen using an excimer source using at least one relatively intense wavelength from the source, detecting radiation received from the illuminated portion of the specimen, analyzing the detected radiation for potential defects present in the specimen portion.

Abstract: A high performance objective having very small central obscuration, an external pupil for apertureing and Fourier filtering, loose manufacturing tolerances, large numerical aperture, long working distance, and a large field of view is presented. The objective is preferably telecentric. The design is ideally suited for both broad-band bright-field and laser dark field imaging and inspection at wavelengths in the UV to VUV spectral range.

Abstract: A relatively high NA objective employed for use in imaging a specimen and method for imaging a specimen is provided. The objective comprises a lens group having at least one focusing lens configured to receive light energy and form an intermediate image, at least one field lens oriented to receive the intermediate image and provide intermediate light energy, and a Mangin mirror arrangement positioned to receive the intermediate light energy and apply light energy to the specimen. One or more elements may employ an aspheric surface. The objective may provide, in certain instances, an uncorrected spectral bandwidth up to approximately 193 to 266 nanometers and can provide numerical apertures in excess of 0.9. Elements are less than 100 millimeters in diameter and may fit within a standard microscope. The field lens may comprise more than one lens and may be formed of a material different from at least one other lens in the objective.

Abstract: A variable modulated transfer function (MTF) design employing a variable gate voltage source for use in inspecting specimens is disclosed. The design applies a variable gate voltage to each pixel of a sensor, wherein applying the variable gate voltage to each pixel adjusts the MTF of the pixel. MTF adjustment improves adverse effects encountered during inspection, such as aliasing and maintaining contrast.

Abstract: A relatively high spectral bandwidth objective employed for use in imaging a specimen and method for imaging a specimen is provided. The objective comprises a lens group comprising at least one focusing lens configured to receive light energy and form focused light energy. The focused light energy forms an intermediate image. The objective further comprises at least one field lens located in proximity to an intermediate image, and a catadioptric arrangement positioned to receive the intermediate light energy from the at and form controlled light energy. The catadioptric arrangement may comprise at least one Mangin element and can include a meniscus lens element.

Abstract: A method and apparatus for propagating charge through a time division and integration (TDI) sensor is provided. The method and apparatus may be used with the TDI sensor to inspect specimens, the TDI sensor operating to advance an accumulated charge between gates of the TDI sensor. The design comprises controlling voltage waveform shapes for waveforms advancing the accumulated charge between gates in a substantially nonsquare waveform, such as a composite, sinusoidal, or other shaped waveform. Controlling voltage waveform shapes operates at different voltage phases in adjacent gates to provide a substantially de minimis net voltage.

Abstract: A system for multiple mode imaging is disclosed. The catadioptric system has an NA greater than 0.65, and preferably greater than 0.9, highly corrected for low and high order monochromatic aberrations. The system employs unique illumination entrances and optics to collect reflected, diffracted, and scattered light over a range of angles. Multiple imaging modes are possible by varying the illumination geometry and apertures at the pupil plane. Illumination can enter the catadioptric optical sytems using an auxiliary beamsplitter or mirror, or through the catadioptric elements at any angle from 0 to 85 degrees from vertical. The system may employ a relayed pupil plane, used to select different imaging modes, provide simultaneous operation of different imaging modes, Fourier filtering, and other pupil shaping operations.

Abstract: A laser illuminator for use in an inspection system, such as a semiconductor wafer inspection system or photomask inspection system is provided. The gain medium in the illuminator comprises optical fiber, and amplification, beam splitting, frequency and/or bandwidth conversion, peak power reduction, and q-switching or mode locking may be employed. Certain constructs including doped fiber, gratings, saturable absorbers, and laser diodes are disclosed to provide enhanced illumination.