Abstract: An inspection system including an optical system (optics) to direct light from an illumination source to a sample, and to direct light reflected/scattered from the sample to one or more image sensors. At least one image sensor of the system is formed on a semiconductor membrane including an epitaxial layer having opposing surfaces, with circuit elements formed on one surface of the epitaxial layer, and a pure boron layer and a doped layer on the other surface of the epitaxial layer. The image sensor may be fabricated using CCD (charge coupled device) or CMOS (complementary metal oxide semiconductor) technology. The image sensor may be a two-dimensional area sensor, or a one-dimensional array sensor. The image sensor can be included in an electron-bombarded image sensor and/or in an inspection system.

Abstract: A multiple-column-per-channel image CCD sensor utilizes a multiple-column-per-channel readout circuit including connected transfer gates that alternately transfer pixel data (charges) from a group of adjacent pixel columns to a shared output circuit at high speed with low noise. Charges transferred along the adjacent pixel columns at a line clock rate are alternately passed by the transfer gates to a summing gate that is operated at multiple times the line clock rate to pass the image charges to the shared output circuit. A symmetrical fork-shaped diffusion is utilized in one embodiment to merge the image charges from the group of related pixel columns. A method of driving the multiple-column-per-channel CCD sensor with line clock synchronization is also described. A method of inspecting a sample using the multiple-column-per-channel CCD sensor is also described.

Abstract: An inspection system/method in which first optics direct continuous wave (CW) light at 181-185 nm to an inspected article, and second optics redirect image information affected by the article to detectors. A laser assembly generates the CW light by generating fourth harmonic light from first fundamental CW light having a first wavelength between 1 and 1.1 ?m, generating fifth harmonic light by mixing the fourth harmonic light with the first fundamental CW light, and mixing the fifth harmonic light with second light having a second wavelength between 1.26 and 1.82 ?m. An external cavity mixes the first light and the fourth harmonic light using a first nonlinear crystal. The CW light is generated using a second cavity that passes circulated second fundamental or signal CW light through a second nonlinear crystal, and directing the fifth harmonic light through the second nonlinear crystal.

Abstract: A system for measuring an overlay error of a sample is disclosed. The system may include a broadband illumination source configured to emit broadband illumination. The system may also include one or more optical elements configured to direct the broadband illumination to a target disposed on the sample, wherein the one or more optical elements are configured to collect illumination from the target and direct it to a spectrometer, wherein the spectrometer is configured to disperse multiple wavelengths of the illumination collected from the sample to multiple elements of a sensor to generate a plurality of signals. The system may also include a controller configured to calculate an overlay error between a first structure and a second structure of the target by comparing the plurality of signals with a plurality of calculated signals.

Abstract: A dual-column-parallel image CCD sensor utilizes a dual-column-parallel readout circuit including two pairs of cross-connected transfer gates to alternately transfer pixel data (charges) from a pair of adjacent pixel columns to a shared output circuit at high speed with low noise. Charges transferred along the two adjacent pixel columns at a line clock rate are alternately passed by the transfer gates to a summing gate that is operated at twice the line clock rate to pass the image charges to the shared output circuit. A symmetrical Y-shaped diffusion is utilized in one embodiment to merge the image charges from the two pixel columns. A method of driving the dual-column-parallel CCD sensor with line clock synchronization is also described. A method of inspecting a sample using the dual-column-parallel CCD sensor is also described.

Abstract: A laser system includes a nonlinear optical (NLO) crystal, wherein the NLO crystal is annealed within a selected temperature range. The NLO crystal is passivated with at least one of hydrogen, deuterium, a hydrogen-containing compound or a deuterium-containing compound to a selected passivation level. The system further includes at least one light source, wherein at least one light source is configured to generate light of a selected wavelength and at least one light source is configured to transmit light through the NLO crystal. The system further includes a crystal housing unit configured to house the NLO crystal.

Abstract: A dual-column-parallel image CCD sensor utilizes a dual-column-parallel readout circuit including two pairs of cross-connected transfer gates to alternately transfer pixel data (charges) from a pair of adjacent pixel columns to a shared output circuit at high speed with low noise. Charges transferred along the two adjacent pixel columns at a line clock rate are alternately passed by the transfer gates to a summing gate that is operated at twice the line clock rate to pass the image charges to the shared output circuit. A symmetrical Y-shaped diffusion is utilized in one embodiment to merge the image charges from the two pixel columns. A method of driving the dual-column-parallel CCD sensor with line clock synchronization is also described. A method of inspecting a sample using the dual-column-parallel CCD sensor is also described.

Abstract: An inspection system including an optical system (optics) to direct light from an illumination source to a sample, and to direct light reflected/scattered from the sample to one or more image sensors. At least one image sensor of the system is formed on a semiconductor membrane including an epitaxial layer having opposing surfaces, with circuit elements formed on one surface of the epitaxial layer, and a pure boron layer and a doped layer on the other surface of the epitaxial layer. The image sensor may be fabricated using CCD (charge coupled device) or CMOS (complementary metal oxide semiconductor) technology. The image sensor may be a two-dimensional area sensor, or a one-dimensional array sensor. The image sensor can be included in an electron-bombarded image sensor and/or in an inspection system.

Abstract: An image sensor for short-wavelength light includes a semiconductor membrane, circuit elements formed on one surface of the semiconductor membrane, and a pure boron layer on the other surface of the semiconductor membrane. An anti-reflection or protective layer is formed on top of the pure boron layer. This image sensor has high efficiency and good stability even under continuous use at high flux for multiple years. The image sensor may be fabricated using CCD (charge coupled device) or CMOS (complementary metal oxide semiconductor) technology. The image sensor may be a two-dimensional area sensor, or a one-dimensional array sensor.

Abstract: A laser assembly generates continuous wave (CW) laser output light in the range of approximately 181 nm to approximately 185 nm by generating fourth harmonic light from first fundamental CW light having a first fundamental wavelength between 1 ?m and 1.1 ?m, generating fifth harmonic light by mixing the fourth harmonic light with the first fundamental CW light, and then mixing the fifth harmonic light with second fundamental or signal CW light having a second wavelength between 1.26 ?m and 1.82 ?m. The fifth harmonic light is generated using an external cavity that circulates first fundamental CW light through a first nonlinear crystal, and by directing the fourth harmonic light through the first nonlinear crystal. The laser output light is generated using a second cavity that passes circulated second fundamental or signal CW light through a second nonlinear crystal, and directing the fifth harmonic light through the second nonlinear crystal.

Abstract: A photocathode is formed on a monocrystalline silicon substrate having opposing illuminated (top) and output (bottom) surfaces. To prevent oxidation of the silicon, a thin (e.g., 1-5 nm) boron layer is disposed directly on the output surface using a process that minimizes oxidation and defects. An optional second boron layer is formed on the illuminated (top) surface, and an optional anti-reflective material layer is formed on the second boron layer to enhance entry of photons into the silicon substrate. An optional external potential is generated between the opposing illuminated (top) and output (bottom) surfaces. The photocathode forms part of novel electron-bombarded charge-coupled device (EBCCD) sensors and inspection systems.

Abstract: In-situ passivation of a nonlinear optical (NLO) crystal during operation of a characterization tool includes converting a laser beam of a selected wavelength to a converted laser beam of a harmonic wavelength via a nonlinear optical (NLO) crystal and passivating the NLO crystal during conversion to the converted laser beam of the harmonic wavelength.

Abstract: An electron source is formed on a silicon substrate having opposing first and second surfaces. At least one field emitter is prepared on the second surface of the silicon substrate to enhance the emission of electrons. To prevent oxidation of the silicon, a thin, contiguous boron layer is disposed directly on the output surface of the field emitter using a process that minimizes oxidation and defects. The field emitter can take various shapes such as pyramids and rounded whiskers. One or several optional gate layers may be placed at or slightly lower than the height of the field emitter tip in order to achieve fast and accurate control of the emission current and high emission currents. The field emitter can be p-type doped and configured to operate in a reverse bias mode or the field emitter can be n-type doped.

Abstract: A focusing EBCCD includes a control device positioned between a photocathode and a CCD. The control device has a plurality of holes therein, wherein the plurality of holes are formed perpendicular to a surface of the photocathode, and wherein a pattern of the plurality of holes is aligned with a pattern of pixels in the CCD. Each hole is surrounded by at least one first electrode, which is formed on a surface of the control device facing the photocathode. The control device may include a plurality of ridges between the holes. The control device may be separated from the photocathode by approximately half a shorter dimension of a CCD pixel or less. A plurality of first electrodes may be provided, wherein each first electrode surrounds a given hole and is separated from the given hole by a gap.

Abstract: A photocathode is formed on a monocrystalline silicon substrate having opposing illuminated (top) and output (bottom) surfaces. To prevent oxidation of the silicon, a thin (e.g., 1-5 nm) boron layer is disposed directly on the output surface using a process that minimizes oxidation and defects. An optional second boron layer is formed on the illuminated (top) surface, and an optional anti-reflective material layer is formed on the second boron layer to enhance entry of photons into the silicon substrate. An optional external potential is generated between the opposing illuminated (top) and output (bottom) surfaces. The photocathode forms part of novel electron-bombarded charge-coupled device (EBCCD) sensors and inspection systems.

Abstract: A laser assembly for generating laser output light at an output wavelength of approximately 183 nm includes a fundamental laser, an optical parametric system (OPS), a fifth harmonic generator, and a frequency mixing module. The fundamental laser generates fundamental light at a fundamental frequency. The OPS generates a down-converted signal at a down-converted frequency. The fifth harmonic generator generates a fifth harmonic of the fundamental light. The frequency mixing module mixes the down-converted signal and the fifth harmonic to produce the laser output light at a frequency equal to a sum of the fifth harmonic frequency and the down-converted frequency. The OPS generates the down-converted signal by generating a down-converted seed signal at the down-converted frequency, and then mixing the down-converted seed signal with a portion of the fundamental light.

Abstract: Pixel aperture size adjustment in a linear sensor is achieved by applying more negative control voltages to central regions of the pixel's resistive control gate, and applying more positive control voltages to the gate's end portions. These control voltages cause the resistive control gate to generate an electric field that drives photoelectrons generated in a selected portion of the pixel's light sensitive region into a charge accumulation region for subsequent measurement, and drives photoelectrons generated in other portions of the pixel's light sensitive region away from the charge accumulation region for subsequent discard or simultaneous readout. A system utilizes optics to direct light received at different angles or locations from a sample into corresponding different portions of each pixel's light sensitive region.

Abstract: A laser assembly generates continuous wave (CW) laser output light in the range of approximately 181 nm to approximately 185 nm by generating fourth harmonic light from first fundamental CW light having a first fundamental wavelength between 1 ?m and 1.1 ?m, generating fifth harmonic light by mixing the fourth harmonic light with the first fundamental CW light, and then mixing the fifth harmonic light with second fundamental or signal CW light having a second wavelength between 1.26 ?m and 1.82 ?m. The fifth harmonic light is generated using an external cavity that circulates first fundamental CW light through a first nonlinear crystal, and by directing the fourth harmonic light through the first nonlinear crystal. The laser output light is generated using a second cavity that passes circulated second fundamental or signal CW light through a second nonlinear crystal, and directing the fifth harmonic light through the second nonlinear crystal.

Abstract: An electron source is formed on a silicon substrate having opposing first and second surfaces. At least one field emitter is prepared on the second surface of the silicon substrate to enhance the emission of electrons. To prevent oxidation of the silicon, a thin, contiguous boron layer is disposed directly on the output surface of the field emitter using a process that minimizes oxidation and defects. The field emitter can take various shapes such as pyramids and rounded whiskers. One or several optional gate layers may be placed at or slightly lower than the height of the field emitter tip in order to achieve fast and accurate control of the emission current and high emission currents. The field emitter can be p-type doped and configured to operate in a reverse bias mode or the field emitter can be n-type doped.

Abstract: An inspection system including an optical system (optics) to direct light from an illumination source to a sample, and to direct light reflected/scattered from the sample to one or more image sensors. At least one image sensor of the system is formed on a semiconductor membrane including an epitaxial layer having opposing surfaces, with circuit elements formed on one surface of the epitaxial layer, and a pure boron layer on the other surface of the epitaxial layer. The image sensor may be fabricated using CCD (charge coupled device) or CMOS (complementary metal oxide semiconductor) technology. The image sensor may be a two-dimensional area sensor, or a one-dimensional array sensor. The image sensor can be included in an electron-bombarded image sensor and/or in an inspection system.