Abstract: The present application discloses a method for manufacturing semiconductor devices having gate dielectric layers at different thickness. The gate dielectric layers having other than the minimum thickness are respectively formed by the following steps: step 1: forming a first mask layer; step 2: etching the first mask layer to form a first opening; step 3: etching a semiconductor substrate at the bottom of the first opening to form a second groove; step 4: filling the second groove and the first opening with the second material layer; step 5: etching back the second material layer to form the gate dielectric layer, such that the second material layer is flush with the top surface of the semiconductor substrate; and step 6: removing the first mask layer.

Abstract: A method for manufacturing a sigma-shaped groove in a semiconductor substrate includes: step 1: performing the first etching to form a U-shaped groove in a selected area of the substrate; step 2: performing a second etching configured to expand an opening width of the top sub-groove outward laterally, without changing an opening width of the bottom sub-groove and a depth of the groove; and step 3: performing the third etching which has different etching rates on different crystal surfaces of the semiconductor substrate to further expand the groove into a sigma-shaped groove with a sigma-shaped cross section. An increase of the opening width of the top sub-groove shifts the upper side surface towards an outer side of the sigma-shaped groove, resulting in an upward shift of the apex and reduces a vertical spacing between the apex and top surface of the semiconductor substrate, thereby improving the device performance.

Abstract: Various methods, systems and apparatus are provided for imaging and sensing using interferometry. In one example, a system includes an interferometer; a light source that can provide light to the interferometer at multiple wavelengths (?i); and optical path delay (OPD) modifying optics that can enhance contrast in an interferometer output associated with a sample. The light can be directed to the sample by optics of the interferometer. The interferometer output can be captured by a detector (e.g., a camera) at each of the multiple wavelengths (?i). In another example, an apparatus includes an add-on unit containing OPD that can enhance contrast in an interferometer output associated with a sample illuminated by light at a defined wavelength (?i). A detector can be attached to the add-on unit to record the interferometer output at the defined wavelength (?i).

Abstract: The present application discloses a method for manufacturing semiconductor devices having gate dielectric layers at different thickness. The gate dielectric layers having other than the minimum thickness are respectively formed by the following steps: step 1: forming a first mask layer; step 2: etching the first mask layer to form a first opening; step 3: etching a semiconductor substrate at the bottom of the first opening to form a second groove; step 4: filling the second groove and the first opening with the second material layer; step 5: etching back the second material layer to form the gate dielectric layer, such that the second material layer is flush with the top surface of the semiconductor substrate; and step 6: removing the first mask layer.

Abstract: Various methods, systems and apparatus are provided for imaging and sensing using interferometry. In one example, a system includes an interferometer; a light source that can provide light to the interferometer at multiple wavelengths (?i); and optical path delay (OPD) modifying optics that can enhance contrast in an interferometer output associated with a sample. The light can be directed to the sample by optics of the interferometer. The interferometer output can be captured by a detector (e.g., a camera) at each of the multiple wavelengths (?i). In another example, an apparatus includes an add-on unit containing OPD that can enhance contrast in an interferometer output associated with a sample illuminated by light at a defined wavelength (?i). A detector can be attached to the add-on unit to record the interferometer output at the defined wavelength (?i).

Abstract: Disclosed herein are interferometric systems having reflective chambers and related methods. According to an aspect, an interferometric system may include a light source for generating an illumination beam that propagates towards a sample. A sample holder may hold the sample and include a partially reflective cover for allowing a first portion of the illumination beam to pass therethrough to interact with the sample to produce a sample beam that propagates substantially along an optical axis. The cover may be oriented at an angle for reflecting a second portion of the illumination beam to produce a reference beam that propagates at a predetermined angle with respect to the optical axis. An imaging module may redirect the reference beam towards the optical axis at a detection plane. A detector may intercept the sample and reference beams and may generate a holographic representation of the sample based on the beams.

Abstract: Optical fiber-based angle-resolved low coherence interferometric systems and methods are disclosed for imaging of scattering samples and measurement of optical and structural properties. A single-mode collection optical fiber can be employed and scanned to collect an angular scattering distribution of scattered light from the sample. Use of a single-mode collection optical fiber can reduce cost, increase signal accuracy, and provide compatibility with optical coherence tomography systems, as examples. In certain embodiments, collected angular scatterings of light from the sample are cross-correlated with a reference signal to provide an angular scattering distribution of scattering of light from the sample. The angular scattering distribution can be spectrally dispersed to yield an angle-resolved, spectrally-resolved cross-correlation profile having depth-resolved information about the sample at the scattering angles.

Abstract: Disclosed herein are interferometric systems having reflective chambers and related methods. According to an aspect, an interferometric system may include a light source for generating an illumination beam that propagates towards a sample. A sample holder may hold the sample and include a partially reflective cover for allowing a first portion of the illumination beam to pass therethrough to interact with the sample to produce a sample beam that propagates substantially along an optical axis. The cover may be oriented at an angle for reflecting a second portion of the illumination beam to produce a reference beam that propagates at a predetermined angle with respect to the optical axis. An imaging module may redirect the reference beam towards the optical axis at a detection plane. A detector may intercept the sample and reference beams and may generate a holographic representation of the sample based on the beams.

Abstract: A method of coupling a silica fiber and a sapphire fiber includes providing a silica fiber having a doped core and a cladding layer, with the doped core having a prescribed diameter, providing a sapphire fiber having a diameter less than the doped core, placing an end of the sapphire fiber in close proximity to an end of the silica fiber, applying a heat source to the end of silica fiber and introducing the end of sapphire fiber into the heated doped core of the silica fiber to produce a coupling between the silica and sapphire fibers.

Abstract: A fiber optic sensor has a hollow tube bonded to the endface of an optical fiber, and a diaphragm bonded to the hollow tube. The fiber endface and diaphragm comprise an etalon cavity. The length of the etalon cavity changes when applied pressure or acceleration flexes the diaphragm. The entire structure can be made of fused silica. The fiber, tube, and diaphragm can be bonded with a fusion splice. The present sensor is particularly well suited for measuring pressure or acceleration in high temperature, high pressure and corrosive environments (e.g., oil well downholes and jet engines). The present sensors are also suitable for use in biological and medical applications.

Abstract: A fiber optic sensor has a hollow tube bonded to the endface of an optical fiber, and a diaphragm bonded to the hollow tube. The fiber endface and diaphragm comprise an etalon cavity. The length of the etalon cavity changes when applied pressure or acceleration flexes the diaphragm. The entire structure can be made of fused silica. The fiber, tube, and diaphragm can be bonded with a fusion splice. The present sensor is particularly well suited for measuring pressure or acceleration in high temperature, high pressure and corrosive environments (e.g., oil well downholes and jet engines). The present sensors are also suitable for use in biological and medical applications.