The present document relates to a method of monitoring an overlay or alignment between a first and second layer of a semiconductor using a scanning probe microscopy system. The method comprises scanning the substrate surface using a probe tip for obtaining a measurement of a topography of the first and second layer in at least one scanning direction. At least one pattern template is generated which is matched with the topography of the first layer for determining a first candidate pattern. The first candidate pattern is matched with the measured second topography for obtaining a second candidate pattern to represent the measured topography of the second layer. Feature characteristics of device features are determined from both the first and second candidate pattern, and these are used to calculate one or more overlay parameters or alignment parameters.

A scanning probe microscope is provided comprising a scanning probe (10), a holder (5) for holding a sample (SMP) in an environment free from liquid. A scanning arrangement (20) is provided therein for inducing a relative motion of the scanning probe (10) with respect to said sample (SMP) along a surface of the sample (SMP). A driver (30) generates a drive signal (Sd) to induce an oscillating motion of the scanning probe (10) relative to the surface of the sample to be scanned. A measuring unit (40) measure a deflection of the scanning probe (10), and provides a deflection signal (Sδ) indicative for said deflection. An amplitude detector (50) detects an amplitude of the oscillating motion as indicated by the deflection signal (Sδ) and provides an amplitude signal (Sa) indicative for the amplitude. The scanning probe (10) is at least partly arranged in a liquid (L) to dampen motion of said scanning probe, and therewith has a quality factor Q which is less than or equal than 5. The scanning probe (10) is accommodated in a casing (90) comprising said liquid (L), the scanning probe (10) comprising a flexible carrier (11), the flexible carrier having a movable part provided with a tip (12), which tip (12) extends through an opening (91) in said casing.

The present invention relates to a method and system for quantitatively evaluating surface roughness of an organic pore of kerogen in shale. The method includes: making a shale sample; applying a circle of silver-painted conductive tape on the edge of the shale sample to obtain a processed sample; conducting image scanning on the processed sample to obtain a scanned image; determining a kerogen area according to the scanned image; determining an organic pore area according to the kerogen area; carrying out gridding treatment on the organic pore area to obtain multiple grid cells; adopting double integral calculation on each of the grid cells to obtain the areas of the multiple grid cells; summing each of the areas to obtain the surface area of the organic pore; and evaluating surface roughness of the organic pore according to the surface area of the pore.

A method for determining a value of a local contact potential difference by noncontact atomic force microscopy. For one or more cantilever positions above a surface of a sample: i) determining two distinct voltage values of DC voltage applied between an oscillating cantilever and the sample, and ii) determining, by one or more processors, a value of a local contact potential difference based, at least in part, on the two distinct voltage values that were determined.

A method for determining a value of a local contact potential difference by noncontact atomic force microscopy. For one or more cantilever positions above a surface of a sample: i) determining two distinct voltage values of DC voltage applied between an oscillating cantilever and the sample, and ii) determining, by one or more processors, a value of a local contact potential difference based, at least in part, on the two distinct voltage values that were determined.

An ultrasound sub-surface probe microscopy device (1) is provided comprising a stage (10), a signal generator (20), a scanning head (30), a signal processor (50) and a scanning mechanism (16). In use, the stage (10) carries a sample (11) and the scanning M mechanism (16) provides for a relative displacement between the sample (11) and the scanning head (30), along the surface of the sample. The scanning head (30) comprises an actuator (31) configured to generate in response to a drive signal (S.sub.dr) from the signal generator (20) an ultrasound acoustic input signal (I.sub.ac). The generated ultrasound acoustic input signal (I.sub.ac) has at least one acoustic input signal component (I.sub.ac1) with a first angular frequency (ω1). The scanning head (30) further comprises a tip (32) to transmit the acoustic input signal (I.sub.ac) through a tip-sample interface (12) as an acoustic wave (W.sub.ac) into the sample. Due to a non-linear interaction in the tip-sample interface (12) at least one up mixed acoustic signal component (W.sub.ac2) in said acoustic wave that has a second angular frequency (ω2) higher than the first angular frequency (ω1) Contrary to known approaches, the sensor signal (S.sub.sense) provided by the sensor facility is indicative for a contribution (W′.sub.ac2) of the at least one up mixed acoustic signal component in reflections (W′.sub.ac) of the acoustic wave within the sample (11). Therewith a relatively high resolution can be achieved with which subsurface features can be detected.

A method of evaluating a thickness of a film on a substrate includes detecting atomic force responses of the film to exposure of electromagnetic radiation in the infrared portion of the electromagnetic spectrum. The use of atomic force microscopy to evaluate thicknesses of thin films avoids underlayer noise commonly encountered when optical metrology techniques are utilized to evaluate film thicknesses. Such underlayer noise adversely impacts the accuracy of the thickness evaluation.

The present document relates to a heterodyne scanning probe microscopy (SPM) method for subsurface imaging, and includes: applying an acoustic input signal to a sample and sensing an acoustic output signal using a probe. The acoustic input signal comprises a plurality of signal components at unique frequencies, including a carrier frequency and at least two excitation frequencies. The carrier frequency and the excitation frequencies form a group of frequencies, which are distributed with an equal difference frequency between each two subsequent frequencies of the group. The difference frequency is below a sensitivity threshold frequency of the cantilever for enabling sensing of the acoustic output signal. The document also describes an SPM system.

The present document relates to a heterodyne scanning probe microscopy (SPM) method for subsurface imaging, and includes: applying an acoustic input signal to a sample and sensing an acoustic output signal using a probe. The acoustic input signal comprises a plurality of signal components at unique frequencies, including a carrier frequency and at least two excitation frequencies. The carrier frequency and the excitation frequencies form a group of frequencies, which are distributed with an equal difference frequency between each two subsequent frequencies of the group. The difference frequency is below a sensitivity threshold frequency of the cantilever for enabling sensing of the acoustic output signal. The document also describes an SPM system.

A method and system for performing subsurface atomic force microscopy measurements, the system comprising: a signal source for generating an drive signal; a transducer configured to receive the drive signal for converting the drive signal into vibrational waves and coupling said vibrational waves into a stack comprising a sample for interaction with subsurface features within said sample; cantilever tip for contacting the sample for measuring surface displacement resulting from the vibrational waves to determine subsurface features; wherein the system includes a measurement device for measuring a measurement signal returning from the transducer during and/or in between the subsurface atomic force microscopy measurements.