Abstract: A spectrophotometer capable of high spectral resolution (e.g., in the GHz range) is presented. The spectrophotometer includes a container for holding a sample, an arrayed-waveguide grating coupled to the sample holder, and a detector array coupled to the arrayed-waveguide grating. The arrayed-waveguide grating may be a monolithic chip, and the container may be integrated into the chip. An integrated container may be a microfluidic channel formed through the layers in the chip and positioned in such a way that light is transferable from the microfluidic channel to the waveguides of the arrayed-waveguide grating. The invention is also a method of making the spectrophotometer. The method entails providing an arrayed-waveguide grating having an input end and an output end, coupling a container to the input end, wherein the container is capable of holding a sample, and coupling a detector array to the output end of the arrayed-waveguide grating.

Abstract: Systems and methods for stabilizing a CO2 laser are disclosed. The system includes a detector unit for measuring the power in a select portion of the output beam. The detector unit generates an electrical signal corresponding to the measured power. The modulation frequency of the signal used to modulate the relatively high-frequency radio-frequency (RF) pump signal is filtered from the electrical signal. The filtered electrical signal is then-compared to a desired value for the output power in the output beam. Based on the comparison, a modulation control signal for modulating the RF pump signal is formed. The modulation control signal has a varying duty cycle that varies the amount of laser pump power to reduce or eliminate the measured variations in the output beam power. The result is an output beam power that remains stable over time.

Abstract: Systems and methods for stabilizing a CO2 laser are disclosed. The system includes a detector unit for measuring the power in a select portion of the output beam. The detector unit generates an electrical signal corresponding to the measured power. The modulation frequency of the signal used to modulate the relatively high-frequency radio-frequency (RF) pump signal is filtered from the electrical signal. The filtered electrical signal is then compared to a desired value for the output power in the output beam. Based on the comparison, a modulation control signal for modulating the RF pump signal is formed. The modulation control signal has a varying duty cycle that varies the amount of laser pump power to reduce or eliminate the measured variations in the output beam power. The result is an output beam power that remains stable over time.

Abstract: Methods and apparatus (100) for scanning a surface (12) of a substrate (10) with an obliquely incident radiation beam (20) over a select scan path (210) to avoid damage (30) to the curved edge (14) of the substrate. The methods and apparatus allow for the substrate edge to be irradiated with the full intensity of the radiation beam, provided that the edge crossing positions avoid a region where the polar angle is less than a scan path critical (SPC) polar angle (?C). At the SPC polar angle the temperatures produced by scanning the beam on the substrate surface and on the edge are the same. The scan path is arranged so the edge crossing positions are located where the polar angle corresponding to each meets or exceeds the SPC polar angle. Ensuring that the substrate edge temperature (TE) remains at or below the substrate surface temperature (TS). The invention has particular utility in laser thermal processing (LTP) of circular silicon substrates when forming transistor-based integrated circuits.

Abstract: Methods and apparatus (100) for scanning a surface (12) of a substrate (10) with an obliquely incident radiation beam (20) over a select scan path (210) to avoid damage (30) to the curved edge (14) of the substrate. The methods and apparatus allow for the substrate edge to be irradiated with the full intensity of the radiation beam, provided that the edge crossing positions avoid a region where the polar angle is less than a scan path critical (SPC) polar angle (?C). At the SPC polar angle the temperatures produced by scanning the beam on the substrate surface and on the edge are the same. The scan path is arranged so the edge crossing positions are located where the polar angle corresponding to each meets or exceeds the SPC polar angle. Ensuring that the substrate edge temperature (TE) remains at or below the substrate surface temperature (TS). The invention has particular utility in laser thermal processing (LTP) of circular silicon substrates when forming transistor-based integrated circuits.

Abstract: An optical device that includes an input region, an output region, and an arrayed waveguide grating between the input region and the output region is presented. The input region includes a first input waveguide set and a second input waveguide set, and the output region includes a first output waveguide set and a second output waveguide set. The arrayed waveguide grating is shared by the signals that travel from the input region to the output region. The device is capable of simultaneously functioning as a multiplexer and a demultiplexer, thereby reducing the cost and complexity of a dual-function optical device. Where the arrayed waveguide grating is used for multiplexing, the optical device receives demultiplexed input signals and generates a multiplexed signal. Where the arrayed waveguide grating is used for demultiplexing, the optical device receives a multiplexed input signal and generates a set of demultiplexed signals.

Abstract: A heat shield (10) that facilitates thermally processing a substrate (22) with a radiation beam (150) is disclosed. The heat shield is in the form of a cooled plate adapted to allow the radiation beam to communicate with the substrate upper surface (20) over a radiation beam path (BP), either through an aperture or a transparent region. The heat shield has an operating position that forms a relatively small gap (170) between the lower surface (54) of the heat shield and the upper surface of the wafer. The gap is sized such that the formation of convection cells (200) is suppressed during substrate surface irradiation. If convection cells do form, they are kept out of the radiation beam path. This prevents the radiation beam from wandering from the desired radiation beam path, which in turn allows for uniform heating of the substrate during thermal processing.

Abstract: Apparatus and method for performing laser thermal annealing (LTA) of a substrate using an annealing radiation beam that is not substantially absorbed in the substrate at room temperature. The method takes advantage of the fact that the absorption of long wavelength radiation (1 micron or greater) in some substrates, such as undoped silicon substrates, is a strong function of temperature. The method includes heating the substrate to a critical temperature where the absorption of long-wavelength annealing radiation is substantial, and then irradiating the substrate with the annealing radiation to generate a temperature capable of annealing the substrate.

Abstract: Apparatus and method for performing laser thermal annealing (LTA) of a substrate using an annealing radiation beam that is not substantially absorbed in the substrate at room temperature. The method takes advantage of the fact that the absorption of long wavelength radiation (1 micron or greater) in some substrates, such as undoped silicon substrates, is a strong function of temperature. The method includes heating the substrate to a critical temperature where the absorption of long-wavelength annealing radiation is substantial, and then irradiating the substrate with the annealing radiation to generate a temperature capable of annealing the substrate.

Abstract: A heat shield (10) that facilitates thermally processing a substrate (22) with a radiation beam (150) is disclosed. The heat shield is in the form of a cooled plate adapted to allow the radiation beam to communicate with the substrate upper surface (20) over a radiation beam path (BP), either through an aperture or a transparent region. The heat shield has an operating position that forms a relatively small gap (170) between the lower surface (54) of the heat shield and the upper surface of the wafer. The gap is sized such that the formation of convection cells (200) is suppressed during substrate surface irradiation. If convection cells do form, they are kept out of the radiation beam path. This prevents the radiation beam from wandering from the desired radiation beam path, which in turn allows for uniform heating of the substrate during thermal processing.

Abstract: Systems and methods for stabilizing a CO2 laser are disclosed. The system includes a detector unit for measuring the power in a select portion of the output beam. The detector unit generates an electrical signal corresponding to the measured power. The modulation frequency of the signal used to modulate the relatively high-frequency radio-frequency (RF) pump signal is filtered from the electrical signal. The filtered electrical signal is then compared to a desired value for the output power in the output beam. Based on the comparison, a modulation control signal for modulating the RF pump signal is formed. The modulation control signal has a varying duty cycle that varies the amount of laser pump power to reduce or eliminate the measured variations in the output beam power. The result is an output beam power that remains stable over time.

Abstract: A spectrophotometer capable of high spectral resolution (e.g., in the GHz range) is presented. The spectrophotometer includes a container for holding a sample, an arrayed-waveguide grating coupled to the sample holder, and a detector array coupled to the arrayed-waveguide grating. The arrayed-waveguide grating may be a monolithic chip, and the container may be integrated into the chip. An integrated container may be a microfluidic channel formed through the layers in the chip and positioned in such a way that light is transferable from the microfluidic channel to the waveguides of the arrayed-waveguide grating. The invention is also a method of making the spectrophotometer. The method entails providing an arrayed-waveguide grating having an input end and an output end, coupling a container to the input end, wherein the container is capable of holding a sample, and coupling a detector array to the output end of the arrayed-waveguide grating.

Abstract: Apparatus and method for performing laser thermal annealing (LTA) of a substrate using an annealing radiation beam that is not substantially absorbed in the substrate at room temperature. The method takes advantage of the fact that the absorption of long wavelength radiation (1 micron or greater) in some substrates, such as undoped silicon substrates, is a strong function of temperature. The method includes heating the substrate to a critical temperature where the absorption of long-wavelength annealing radiation is substantial, and then irradiating the substrate with the annealing radiation to generate a temperature capable of annealing the substrate.

Abstract: Disclosed are first and second embodiments of a 3-channel probe-plate structure of the fiber-optic interferometer, wherein low-coherent-length light from a superluminescent light-emitting diode is split by a tree splitter into three light branches which are coupled as separate light inputs to the probe-pate structure by single-mode, polarization-preserving optical fibers. For each of the 3 channels, the first embodiment of the probe-plate structure comprises an integrated polarizing lithium-niobate Y splitter-modulator for deriving separate reference-arm light and probe-arm light.

Abstract: A light tunnel apparatus (200 or 300) having an output end (56 or 98), for uniformizing light (L) that travels through a light tunnel (30 or 80). The apparatus comprises a light tunnel having first and second sides (36, 40 or 86, 90), and one or more AO modulators (210 or 310) respectively arranged on at least one of the first and second sides. The AO modulators are arranged such that activating the one or more of them causes at least one of the first and second sides to be displaced. This displacement changes the path of light traveling through the light tunnel by an amount sufficient to reduce illumination non-uniformities at the output end. The light tunnel may be a hollow light tunnel (30) with reflective inner surfaces, or a solid light tunnel (80) with a refractive index. A method of uniformizing illumination using a light tunnel is also disclosed.

Abstract: A method and apparatus for measuring microstructures, anistropy and birefringence in polymers using laser scattered light includes a laser which provides a beam that can be conditioned and is directed at a fiber or film which causes the beam to scatter. Backscatter light is received and processed with detectors and beam splitters to obtain data. The data is directed to a computer where it is processed to obtain information about the fiber or film, such as the birefringence and diameter. This information provides a basis for modifications to the production process to enhance the process.