An evaluation method of a silicon wafer allows non-destructive and non-contact inspection of a slip that affects the electrical properties of semiconductor devices, without being subjected to restrictions of the surface condition of silicon wafers or processing contents as much as possible. The evaluation method of a silicon wafer includes a step of section analysis where a surface of a single crystal silicon wafer after thermal processing is divided by equally-spaced lines into sections with an area of 1 mm.sup.2 or more and 25 mm.sup.2 or less and the existence of strain in each of the sections is determined based on a depolarization value of polarized infrared light, and a screening step where the wafer is evaluated as non-defective when the number of adjacent sections being determined to have strain by the section analysis step does not exceed a predetermined threshold value.

The invention relates to a selection method of loss control materials for lost circulation control in fractured reservoirs based on photoelastic experiments. By using the photoelastic material to simulate rigid lost circulation material, obtaining photoelastic images and load curves during a loading process of plugging zones formed by the lost circulation material, selecting the lost circulation material according to structure stability of plugging zones. Based on a relationship between structures and performances and granular matter mechanics, the present method is with high reliable to duly observe distribution and evolution of internal forces in a pressure-bearing process of plugging zones, reveal an instability mechanism of the plugging zone, and optimize the lost circulation material in a targeted manner; the present disclosure based on mesoscopic structure characterization of plugging zones is for a new idea for material selection of deep fractured reservoirs, of good repeatability, simple operation and low economic cost.

The invention provides a glass surface stress meter and multiple-tempered glass surface stress meter, and the glass surface stress meter includes a light source (810, 910), a light refraction element (820, 920) and an imaging unit. The light refraction element (820, 920) is provided at a light-emitting direction of the light source (810, 910) for placing a measured glass (970). The light from the light source (810, 910) comes into the imaging unit to imaging after refracted by the light refractive element (820, 920). The imaging unit includes lens group (830, 940) and a imaging sensor (840, 960). A front end of the lens group is provided at the light-refraction direction of the light refraction element (820, 920) and a back-end is provided with the imaging sensor.

An evaluation method of a silicon wafer allows non-destructive and non-contact inspection of a slip that affects the electrical properties of semiconductor devices, without being subjected to restrictions of the surface condition of silicon wafers or processing contents as much as possible. The evaluation method of a silicon wafer includes a step of section analysis where a surface of a single crystal silicon wafer after thermal processing is divided by equally-spaced lines into sections with an area of 1 mm.sup.2 or more and 25 mm.sup.2 or less and the existence of strain in each of the sections is determined based on a depolarization value of polarized infrared light, and a screening step where the wafer is evaluated as non-defective when the number of adjacent sections being determined to have strain by the section analysis step does not exceed a predetermined threshold value.

Methods and systems for measuring optical properties of transistor channel structures and linking the optical properties to the state of strain are presented herein. Optical scatterometry measurements of strain are performed on metrology targets that closely mimic partially manufactured, real device structures. In one aspect, optical scatterometry is employed to measure uniaxial strain in a semiconductor channel based on differences in measured spectra along and across the semiconductor channel. In a further aspect, the effect of strain on measured spectra is decorrelated from other contributors, such as the geometry and material properties of structures captured in the measurement. In another aspect, measurements are performed on a metrology target pair including a strained metrology target and a corresponding unstrained metrology target to resolve the geometry of the metrology target under measurement and to provide a reference for the estimation of the absolute value of strain.

Methods of improving the measurement of knee stress in an ion-exchanged chemically strengthened Li-containing glass sample that includes a knee are disclosed. One of the methods includes compensating for a shift in the location of the TIR-PR transition location associated with the critical angle location, wherein the shift is due to the presence of a leaky mode. Another method includes applying select criteria to the captured mode spectra image to ensure a high-quality image is used for the knee stress calculation. Another method combines direct and indirect measurements of the knee stress using the mode spectra from multiple samples to obtain greater accuracy and precision as compared to using either the direct measurement method or the indirect measurement method alone. Quality control methods of forming the glass samples using measured mode spectra and related techniques for ensuring an accurate measurement of the knee stress are also disclosed.

A method of inspecting a structure including a photonic material using a movable inspection apparatus includes irradiating a section of the structure, receiving radiation diffracted from a photonic material in the section of the structure, determining a deformation of the photonic material as a function of at least one of i) an intensity of the radiation received ii) a position of the radiation received and iii) a wavelength of the radiation received, and determining if a magnitude of the deformation is higher than a threshold. If the magnitude of the deformation is higher than the threshold data is stored concerning the deformation of the photonic material; contrarily, if the magnitude of the deformation is not higher than the threshold: the inspection at the location of the photonic material is stopped and the inspection apparatus is moved in order to inspect another section of the structure.

Various tactile sensors and associated methods are enabled. For instance, a sensing apparatus comprises a photosensitive sensor. A compound-eye structure is on the photosensitive sensor and an elastomer layer is on the compound-eye structure. A reflective layer is on the elastomer layer, opposite the compound-eye structure and a light source emits light between the reflective layer and the compound-eye structure.

Disclosed is a method of measuring a surface refractive index of a strengthened glass including causing light to enter a surface layer of the strengthened glass through a liquid provided with a refractive index equivalent to that of a surface of the surface layer; a process of causing the light to be emitted from the strengthened glass through the liquid; converting two types of light components into two types of emission line sequences; capturing an image of the two types of emission line sequences; measuring positions of respective emission lines of the two types of emission line sequences from the image; and calculating refractive indexes of a surface of the strengthened glass corresponding to the two types of light components, or refractive index distributions of the strengthened glass in a depth direction from the surface corresponding to the two types of light components.

The hybrid measurement system includes an evanescent prism coupling spectroscopy (EPCS) sub-system and a light-scattering polarimetry (LSP) sub-system. The EPCS sub-system includes an EPCS light source optically coupled to an EPCS detector system through an EPCS coupling prism. The LSP sub-system includes an LSP light source optically coupled to an optical compensator, which in turn is optically coupled to a LSP detector system via a LSP coupling prism. A support structure supports the EPCS and LSP coupling prisms to define a coupling prism assembly, which supports the two prisms at a measurement location. Stress measurements made using the EPCS and LSP sub-systems are combined to fully characterize the stress properties of a transparent chemically strengthened substrate. Methods of processing the EPCS and LSP measurements to improve measurement accuracy are also disclosed.