An electronic circuit includes signal processing electronics. The electronic circuit receives an electrical signal generated by a photodetector based on a light beam from a location on a material including a signal of interest and one or more modulation frequencies. The electronic circuit discriminates a portion of the electrical signal proportional to a characteristic of the signal of interest from other components of the electrical signal using a low pass filter with a transfer function including a notch at a notch frequency corresponding to one of the modulation frequencies. The electronic circuit determines a value for the characteristic of the signal of interest from the discriminated portion of the electrical signal. The signal processing electronics further outputs the value of the characteristic of the signal of interest.

The methods and apparatus provide phase-resolved optical metrology for determining qualities of a substrate and films thereon. Transmitted and reflected signals are coupled using both amplitude and phase information to improve the metrology information obtained from film layers on the substrate.

The present disclosure relates to an optical sensing module, a system and a method for operating the optical sensing system. The optical sensing module includes a light emitter that emits a sensing light in a specific wavelength range and a photodiode unit. The photodiode unit includes a first photodiode used to sense a first wavelength light, a second photodiode used to sense a second wavelength light, and a third photodiode used to sense a third wavelength light. The optical sensing module implements a proximity sensor by operations of the second photodiode and the third photodiode, or a biometric sensor by operations of the first photodiode, the second photodiode, and the third photodiode. The photodiode unit receives a reflected light from an object to be detected so as to determine if the object is proximal, and then determine whether or not the proximal object is human skin.

A laser system includes a nonlinear optical (NLO) crystal, wherein the NLO crystal is annealed within a selected temperature range. The NLO crystal is passivated with at least one of hydrogen, deuterium, a hydrogen-containing compound or a deuterium-containing compound to a selected passivation level. The system further includes at least one light source, wherein at least one light source is configured to generate light of a selected wavelength and at least one light source is configured to transmit light through the NLO crystal. The system further includes a crystal housing unit configured to house the NLO crystal.

A method includes performing Chemical Mechanical Polish (CMP) on a wafer, placing the wafer on a chuck, performing a post-CMP cleaning on the wafer, and determining cleanness of the wafer when the wafer is located on the chuck.

Provided is a method of extracting properties of a layer on a wafer, the method including emitting electromagnetic waves to a lower surface of the wafer, detecting a first electromagnetic wave, that passes through a target layer on an upper surface of the wafer, and a second electromagnetic wave, that is reflected from the target layer, among the electromagnetic waves to obtain data including information about the first electromagnetic wave and the second electromagnetic wave, and separating a first pulse of the first electromagnetic wave and a second pulse of the second electromagnetic wave from each other in the data and obtaining property data of the target layer.

A method is described in which a spectrum of a surface of a photoconductor member is obtained using optical spectroscopy; and an extent of oxidation of the surface is determined based on the obtained spectrum.

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 method includes performing Chemical Mechanical Polish (CMP) on a wafer, placing the wafer on a chuck, performing a post-CMP cleaning on the wafer, and determining cleanness of the wafer when the wafer is located on the chuck.

A reflectance detection method in which a workpiece is irradiated with a laser beam and reflectance is detected, irradiating, with a light amount H0, the workpiece with a laser beam with a first wavelength X1 shorter than a detection-target wavelength X and detecting a light amount H1 of reflected return light, irradiating the workpiece with a laser beam with a second wavelength X2 longer than the detection-target wavelength X with the light amount H0 and detecting a light amount H2 of reflected return light, and employing H calculated based on an expression shown below as the light amount of return light obtained when the workpiece is irradiated with the detection-target wavelength X and calculating reflectance obtained when the workpiece is irradiated with the detection-target wavelength X based on H/H0.

H=H1+(H2H1)(XX1)/(X2X1)