Abstract: A method for nondestructive measurement of an underlying layer thickness includes irradiating, with a pump laser pulse, a sample to induce generation of an acoustic wave in the sample such that the acoustic wave propagates through the sample over time, where the sample includes a substrate, an underlying layer on the substrate, and an overlying layer on the underlying layer and the underlying layer is isolated from an exterior of the sample by at least the overlying layer, irradiating the sample with a probe laser pulse after irradiating the sample with the pump laser pulse, determining a reflectance variation of the sample over time, based on monitoring a variation of a reflection of the probe laser pulse from the sample over time, to generate a first graph showing a variation of reflectance of the sample over time, and determining a thickness of the underlying layer based on the first graph.

Abstract: A method for nondestructive measurement of an underlying layer thickness includes irradiating, with a pump laser pulse, a sample to induce generation of an acoustic wave in the sample such that the acoustic wave propagates through the sample over time, where the sample includes a substrate, an underlying layer on the substrate, and an overlying layer on the underlying layer and the underlying layer is isolated from an exterior of the sample by at least the overlying layer, irradiating the sample with a probe laser pulse after irradiating the sample with the pump laser pulse, determining a reflectance variation of the sample over time, based on monitoring a variation of a reflection of the probe laser pulse from the sample over time, to generate a first graph showing a variation of reflectance of the sample over time, and determining a thickness of the underlying layer based on the first graph.

Abstract: A scanning probe inspector comprises: a probe that includes a cantilever and a tip whose length corresponds to a depth of a trench that is formed in a wafer; a trench detector that acquires location information of the trench using the probe, where the location information includes depth information of the trench; a controller that inserts the tip into a first point where there exists a trench based on the location information of the trench, and moves the tip through the trench using the location information of the trench; and a defect detector that detects a presence of a defect in a sidewall of the trench as the tip is moved through the trench.

Abstract: A scanning probe inspector comprises: a probe that includes a cantilever and a tip whose length corresponds to a depth of a trench that is formed in a wafer; a trench detector that acquires location information of the trench using the probe, where the location information includes depth information of the trench; a controller that inserts the tip into a first point where there exists a trench based on the location information of the trench, and moves the tip through the trench using the location information of the trench; and a defect detector that detects a presence of a defect in a sidewall of the trench as the tip is moved through the trench.