Abstract: A laser-sustained broadband light source is disclosed. The light source may include a gas containment structure, a pump laser source, and a light collector element. The gas containment structure may include a body formed from an optically transparent material, such as fused silica, and one or more windows transmissive to vacuum ultraviolet (VUV) light. The one or more windows may be bonded to one or more extension portions, thereby ensuring a sealed internal gas volume and avoiding exposure of metal components to destructive VUV radiation. The pump laser source may be configured to direct the pump beam into the gas containment structure to sustain a plasma, emitting broadband light through the one or more windows. Optional retroreflectors may be included to enhance light collection efficiency. The light source configuration extends the spectral range into the VUV and/or infrared regions, improves manufacturability, and enhances plasma stability.

Abstract: A laser assembly and a method for generating continuous-wave (CW) light at approximately 193 nm (between 180 nm and 200 nm) and at a power of 1W or higher using two CW laser sources: one laser source generating first fundamental light that is twice frequency doubled or otherwise converted into first CW light having a first deep-ultraviolet (DUV) wavelength between 250 nm and 275 nm, the other laser source generating second CW light having an infrared (IR) wavelength between 1300 nm and 1700 nm. A resonant cavity receives the second CW light and generates enhanced CW light at 100 W or higher. A first non-linear optical (NLO) crystal mixes a first enhanced CW light portion and the first CW light to generate sum-frequency generation (SFG) light having a second DUV wavelength. A second NLO crystal mixes a second enhanced CW light portion and the SFG light to generate output CW light at approximately 193 nm.

Abstract: An image sensor for short-wavelength light includes a semiconductor membrane, circuit elements formed on a first surface of the semiconductor membrane, and a boron-coated, textured surface on a second surface of the semiconductor membrane. The textured surface comprises pseudo-random, periodic, and/or random distribution of upright pyramids, inverted pyramids, and/or nanocones. The textured surface reduces the reflection of incident light across wide bands in the DUV and VUV regimes, thus increasing the amount of light absorbed and improving the efficiency of the image sensor. Reflectance may be further reduced by applying an antireflective coating on the textured surface. The image sensor may be a two-dimensional area sensor, or a one-dimensional array sensor. and incorporated in an inspection system.

Abstract: A method for constructing a periodically-poled nonlinear crystal may include implanting ions in a bulk crystal of strontium tetraborate (SBO) or lithium triborate (LBO) to generate a damaged layer at a predetermined depth, attaching a handle material to the surface of the bulk crystal, cleaving the bulk crystal at the damaged layer to generate a thin plate, and polishing the thin plate to a thickness suitable for quasi-phase-matching (QPM) to generate laser output light having wavelengths in the range of about 120-200 nm. The surfaces of thin plates generated in this way are optically contacted, and resulting stacks are diced and arranged to generate many-layered QPM crystals. Methods, inspection systems, lithography systems and cutting systems incorporating the laser assembly are also described.

Abstract: An image sensor is disclosed. The image sensor may include a plurality of sensing nodes electrically connected to at least one circuit of the circuits, the sensing nodes formed on the first side of a silicon layer adjacent to the circuits. Each sensing node may include a floating diffusion structure connected to one of at least one channel of the circuits and an output circuit. Each sensing node may include a charge reset structure configured to remove a charge from the floating diffusion structure. Each sensing node may include a noise-cancellation gate electrode adjacent to the floating diffusion structure and configured to be driven by a noise-cancellation signal. The image sensor may include a resistive gate electrode configured for at least one of direct current or non-pulsed signals. A charge reset structure of each sensing node may be driven with a voltage following a sinusoidal waveform.

Abstract: An overlay metrology system and method are disclosed. The overlay metrology system may be configured for twice-diffracted light. The overlay metrology system may include a controller. The controller may be configured to receive an image of a metrology target of a sample based on twice-diffracted light associated with one or more illumination beams in accordance with a metrology recipe. The twice-diffracted light may be based on a first diffraction, a re-direction, and a second diffraction of the one or more illumination beams directed twice towards the metrology target. The controller may be configured to generate one or more metrology measurements of the sample based on the image in accordance with the metrology recipe and based on a double-phase-shift of the twice-diffracted light associated with the one or more illumination beams.

Abstract: An inspection system may include illumination optics to direct an illumination beam to a sample and an imaging sub-system to image the sample, where the imaging sub-system includes an objective lens to collect light from the sample as sample light and one or more speckle decorrelation masks in a collection pupil plane configured to control at least one of a phase or an intensity of at least a portion of the sample light. The system may further include a controller to receive two or more inspection images of the sample from the detector, where the two or more inspection images are generated with different configurations of the one or more speckle decorrelation masks selected to at least partially decorrelate the two or more inspection images, combine the inspection images to generate a composite image, and identify defects on the sample based on the composite image.

Abstract: A system for frequency conversion is disclosed. The system includes a nonlinear crystal waveguide formed from strontium tetraborate (SBO) or lithium triborate (LBO). This system is used for second harmonic generation or sum-frequency generation to produce laser output light having wavelengths in the range of about 120-200 nm. Inspection systems, lithography systems and cutting systems incorporating the frequency conversion system are also described.

Abstract: A metrology system is disclosed. The system includes an incoherent illumination source to generate incoherent illumination. The system includes a diffraction grating to split the incoherent illumination. The system includes an objective lens to direct one or more pairs of mutually coherent illumination beams to a metrology target on a sample and collect sample light associated with diffraction of pairs of mutually coherent illumination beams. The system includes a mask configured to pass a single nonzero-order diffraction beam and block a zero-order diffraction beam associated with each of the mutually coherent illumination beams. The system includes a detector configured to generate an image of the metrology target based on light passed by the mask. The system includes a controller communicatively coupled to the detector, including one or more processors configured to generate one or more metrology measurements of the sample based on the image.

Abstract: An illumination source and method are disclosed for improving brightness uniformity. The illumination source may include a laser sustained plasma light source configured to generate a broadband light beam. The illumination source may include an adjustable reflector configured to be adjusted based on one or more signals indicative of a brightness distribution of the broadband light beam emitted along one or more directions. The illumination source may include a set of optics. The set of optics may be configured to split the broadband light beam into a first and second broadband light beam, invert the second broadband light beam, and recombine the first and second broadband light beam. The set of optics may be configured to image the illumination source at least twice, to receive a first and second broadband light beam and then combine the first and second broadband light beam.

Abstract: A tunable laser assembly uses a fundamental wavelength between 1 ?m and 1.1 ?m to alternately generate laser output light at two or more output wavelengths within the range of 184 nm to 200 nm by directing the fundamental light through different regions of a fan-out periodically poled nonlinear crystal to generate corresponding different down-converted signals, and using different nonlinear summing crystals to mix the different down-converted signals with a fifth harmonic of the fundamental wavelength. Each nonlinear summing crystal has a crystal axis aligned at an angle relative to the light propagation direction to facilitate the efficient transmission and summing of the fifth harmonic with an associated down-converted signal.

Abstract: An image sensor and method for fabricating an image sensor. In embodiments, first and second wafers are independently processed with each wafer including part of the final sensor structure. The two wafers are bonded together by an oxide-free wafer bond to form a hybrid wafer combining the two partial sensor structures into one fully functional sensor structure connected by an oxide-free bonding interface enabling continuity of charge transport and minimizing signal loss. Each of the first and second sensor wafers may be fabricated at its optimal process conditions such that the combined sensor can have enhanced sensor capabilities such as quantum efficiency, gain, wavelength range, etc. In embodiments, the first and second sensor wafers may be fabricated in parallel to maximize production throughput.

Abstract: An electron gun for an electron microscope or similar device includes a field emitter cathode having a field emitter protrusion extending from the output surface of a monocrystalline silicon substrate, and electrodes configured to enhance the emission of electrons from a tip portion of the field emitter protrusion to generate a primary electron beam. A contiguous TiN layer is disposed directly on at least the tip portion of the field emitter protrusion using a process that minimizes oxidation and defects in the TiN layer.

Abstract: A method for growing a strontium tetraborate (SrB4O7) crystal is provided. The method includes lowering a seed crystal into a melt having a mixture comprising a source of Sr, B, O, and Cl. The method also includes heating and melting the mixture to a temperature sufficient to form a strontium tetraborate crystal.

Abstract: A method for growing a periodically-poled nonlinear crystal may include placing a seed crystal into a melt to form a seed crystal melt mixture, where the seed crystal may include at least one of strontium tetraborate (SBO) or lithium triborate (LBO), and where the melt includes at least one of a mixture of Sr, B, and O or a mixture of Li, B, and O. The method may further include heating the seed crystal melt mixture to a predetermined temperature until the periodically-poled nonlinear crystal forms.

Abstract: Back-illuminated DUV/VUV/EUV radiation or charged particle image sensors are fabricated using a method that utilizes a plasma atomic layer deposition (plasma ALD) process to generate a thin pinhole-free pure boron layer over active sensor areas. Circuit elements are formed on a semiconductor membrane's frontside surface, and then an optional preliminary hydrogen plasma cleaning process is performed on the membrane's backside surface. The plasma ALD process includes performing multiple plasma ALD cycles, with each cycle including forming an adsorbed boron precursor layer during a first cycle phase, and then generating a hydrogen plasma to convert the precursor layer into an associated boron nanolayer during a second cycle phase. Gasses are purged from the plasma ALD process chamber after each cycle phase. The plasma ALD cycles are repeated until the resulting stack of boron nanolayers has a cumulative stack height (thickness) that is equal to a selected target thickness.

Abstract: An amorphous layer is used as a protective coating for hygroscopic nonlinear optical crystals. The amorphous layer consists of one or more alkali metal borates and/or alkali earth metal borates. The amorphous layer slows or prevents water and/or oxygen from diffusing into the hygroscopic nonlinear optical crystal, thus simplifying handling, storage and operating environmental requirements. One or multiple additional coating layers may be placed on top of the amorphous layer, with the additional coating layers including conventional optical materials. The thicknesses of the amorphous layer and/or additional layers may be chosen to reduce reflectance of the optical component at one or more specific wavelengths. The coated nonlinear optical crystal is used in an illumination source utilized in a semiconductor inspection system, a metrology system, or a lithography system.

Abstract: Image sensors with a tunable floating diffusion (FD) structure for applications such as inspection and metrology are provided. One image sensor includes a sensing node electrically connected to circuits of the image sensor, formed on a first side of a silicon layer adjacent to the circuits, and formed by a Voltage-Controlled Variable Floating Diffusion (VCVFD) structure. The VCVFD structure includes a gate electrode configured to control a variable capacitance of the VCVFD structure via voltage applied to the gate electrode by an electrical connection to the gate electrode. The VCVFD structure converts a charge responsive to electron accumulation in the channel of the circuits to a voltage proportional to an amount of the charge and dependent on the variable capacitance. The VCVFD may also be implemented in an electron-sensor pixel configured for detecting electrons or x-rays as described further herein.

Abstract: Back-illuminated image sensors for detecting short wavelength radiation (e.g., deep ultraviolet (DUV) and vacuum ultraviolet (VUV) light) include a semiconductor membrane, circuit elements formed on a frontside surface of the semiconductor membrane, and a pure boron coating on the backside surface of the semiconductor membrane. A two-part anti-reflective coating is formed over the pure boron coating and includes a thin oxide or nitride protection layer disposed between the pure boron coating and a fluoride-based anti-reflection layer. A method for fabricating the image sensors may include performing plasma atomic layer deposition (plasma ALD) processes to sequentially generate the pure boron coating, the oxide/nitride protection layer and then the fluoride-based anti-reflection layer.

Abstract: Back-illuminated DUV/VUV/EUV radiation or charged particle image sensors are fabricated using a method that utilizes a plasma atomic layer deposition (plasma ALD) process to generate a thin pinhole-free pure boron layer over active sensor areas. Circuit elements are formed on a semiconductor membrane's frontside surface, and then an optional preliminary hydrogen plasma cleaning process is performed on the membrane's backside surface. The plasma ALD process includes performing multiple plasma ALD cycles, with each cycle including forming an adsorbed boron precursor layer during a first cycle phase, and then generating a hydrogen plasma to convert the precursor layer into an associated boron nanolayer during a second cycle phase. Gasses are purged from the plasma ALD process chamber after each cycle phase. The plasma ALD cycles are repeated until the resulting stack of boron nanolayers has a cumulative stack height (thickness) that is equal to a selected target thickness.