Apparatus and methods for forming an image of an object which involves focusing partially to fully spatially-coherent radiation onto a sample and collecting the resulting scattered radiation (the standard data set) on an array detector. In addition to the standard dataset, an additional measurement or plurality of measurements is made of a relatively-unscattered beam, using the array detector, which comprises the modulus enforced probe (MEP) dataset. This MEP dataset serves as an extra constraint, called the MEP constraint, in the phase retrieval algorithm used to reconstruct the image of the object.

An efficient absorption spectroscopy system is provided. The spectroscopy system may be configured to measure solid, liquid or gaseous samples. Vacuum ultra-violet wavelengths may be utilized. Some of the disclosed techniques can be used for detecting the presence of trace concentrations of gaseous species. A preferable gas flow cell is disclosed. Some of the disclosed techniques may be used with a gas chromatography system so as to detect and identify species eluted from the column. Some of the disclosed techniques may be used in conjunction with an electrospray interface and a liquid chromatography system so as to detect and identify gas phase ions of macromolecules produced from solution. Some of the disclosed techniques may be used to characterize chemical reactions. Some of the disclosed techniques may be used in conjunction with an ultra short-path length sample cell to measure liquids.

Methods and systems for performing spectroscopic reflectometry measurements of semiconductor structures at infrared wavelengths are presented herein. In some embodiments measurement wavelengths spanning a range from 750 nanometers to 2,600 nanometers, or greater, are employed. In one aspect, reflectometry measurements are performed at oblique angles to reduce the influence of backside reflections on measurement results. In another aspect, a broad range of infrared wavelengths are detected by a detector that includes multiple photosensitive areas having different sensitivity characteristics. Collected light is linearly dispersed across the surface of the detector according to wavelength. Each different photosensitive area is arranged on the detector to sense a different range of incident wavelengths. In this manner, a broad range of wavelengths are detected with high signal to noise ratio by a single detector.

A device may be provided for element analysis of materials by means of optical emission spectroscopy, particularly by means of laser-induced plasma spectroscopy, said device having: means for exciting a plasma from a partial quantity of a test sample made of the material to be analyzed; means for detecting and for spectral analysis of optical radiation emitted from the plasma; beam guidance means for guiding at least a part of the optical radiation emitted from the plasma to the means for detecting and spectral analysis; and means for flushing at least one partial region of the device with an inert gas, wherein the beam guidance means are at least one capillary tube, which additionally serves to guide the inert gas. A method may be provided for element analysis of materials by means of optical emission spectroscopy using the device.

A method and apparatus for cleaning vacuum ultraviolet (VUV) optics (e.g., one or more mirrors of a VUV) of a substrate inspection system is disclosed. The cleaning system ionizes or disassociates hydrogen gas in a VUV optics environment to generate hydrogen radicals (e.g., H*) or ions (e.g., H.sup.+, H.sub.2.sup.+, H.sub.3.sup.+, which remove water or hydrocarbons from the surface of the one or more mirrors. The one or more VUV mirrors may include a reflective material, such as aluminum. The one or more VUV mirrors may have a protective coating to protect the reflective material from any detrimental reaction to the hydrogen radicals or ions. The protective coating may include a noble metal.

A method and apparatus for cleaning vacuum ultraviolet (VUV) optics (e.g., one or more mirrors of a VUV) of a substrate inspection system is disclosed. The cleaning system ionizes or disassociates hydrogen gas in a VUV optics environment to generate hydrogen radicals (e.g., H*) or ions (e.g., H.sup.+, H.sub.2.sup.+, H.sub.3.sup.+), which remove water or hydrocarbons from the surface of the one or more mirrors. The one or more VUV mirrors may include a reflective material, such as aluminum. The one or more VUV mirrors may have a protective coating to protect the reflective material from any detrimental reaction to the hydrogen radicals or ions. The protective coating may include a noble metal.

An efficient absorption spectroscopy system is provided. The spectroscopy system may be configured to measure solid, liquid or gaseous samples. Vacuum ultra-violet wavelengths may be utilized. Some of the disclosed techniques can be used for detecting the presence of trace concentrations of gaseous species. A preferable gas flow cell is disclosed. Some of the disclosed techniques may be used with a gas chromatography system so as to detect and identify species eluted from the column. Some of the disclosed techniques may be used in conjunction with an electrospray interface and a liquid chromatography system so as to detect and identify gas phase ions of macromolecules produced from solution. Some of the disclosed techniques may be used to characterize chemical reactions. Some of the disclosed techniques may be used in conjunction with an ultra short-path length sample cell to measure liquids.

Methods and systems for performing spectroscopic reflectometry measurements of semiconductor structures at infrared wavelengths are presented herein. In some embodiments measurement wavelengths spanning a range from 750 nanometers to 2,600 nanometers, or greater, are employed. In one aspect, reflectometry measurements are performed at oblique angles to reduce the influence of backside reflections on measurement results. In another aspect, a broad range of infrared wavelengths are detected by a detector that includes multiple photosensitive areas having different sensitivity characteristics. Collected light is linearly dispersed across the surface of the detector according to wavelength. Each different photosensitive area is arranged on the detector to sense a different range of incident wavelengths. In this manner, a broad range of wavelengths are detected with high signal to noise ratio by a single detector.

An efficient absorption spectroscopy system is provided. The spectroscopy system may be configured to measure solid, liquid or gaseous samples. Vacuum ultra-violet wavelengths may be utilized. Some of the disclosed techniques can be used for detecting the presence of trace concentrations of gaseous species. A preferable gas flow cell is disclosed. Some of the disclosed techniques may be used with a gas chromatography system so as to detect and identify species eluted from the column. Some of the disclosed techniques may be used in conjunction with an electrospray interface and a liquid chromatography system so as to detect and identify gas phase ions of macromolecules produced from solution. Some of the disclosed techniques may be used to characterize chemical reactions. Some of the disclosed techniques may be used in conjunction with an ultra short-path length sample cell to measure liquids.

An efficient absorption spectroscopy system is provided. The spectroscopy system may be configured to measure solid, liquid or gaseous samples. Vacuum ultra-violet wavelengths may be utilized. Some of the disclosed techniques can be used for detecting the presence of trace concentrations of gaseous species. A preferable gas flow cell is disclosed. Some of the disclosed techniques may be used with a gas chromatography system so as to detect and identify species eluted from the column. Some of the disclosed techniques may be used in conjunction with an electrospray interface and a liquid chromatography system so as to detect and identify gas phase ions of macromolecules produced from solution. Some of the disclosed techniques may be used to characterize chemical reactions. Some of the disclosed techniques may be used in conjunction with an ultra short-path length sample cell to measure liquids.