A method and device for evaluating inhomogeneous deformations in a first wafer bonded by molecular adhesion to a second wafer. This evaluation method includes the steps of making at least one reading of a plurality of measurement points, the reading corresponding to a surface profile of the first wafer along a predefined direction and over a predefined length, computing a second derivative from the measurement points of the surface profile and evaluating a level of inhomogeneous deformations in the first wafer according to the second derivative.

Advanced interconnect technologies such as Through Silicon Vias (TSVs) have become an integral part of 3-D integration. Methods and systems and provided for laser-based acoustic techniques in which a short laser pulse generates broadband acoustic waves that propagate in the TSV structure. An optical interferometer detects the surface displacement caused by the acoustic waves reflecting within the structure as well as other acoustic waves traveling near the surface that has information about the structure dimensions and irregularities, such as voids. Features of voids, such as their location, are also identified based on the characteristics of the acoustic wave as it propagates through the via. Measurements typically take few seconds per site and can be easily adopted for in-line process monitoring.

A photoacoustic microscope includes: a light source which generates pulse light; a focusing optical system which focuses the pulse light emitted from the light source and irradiate a sample with the focused pulse light; a photoacoustic signal detection unit which detects an acoustic signal generated from the sample through irradiation of the pulse light; an image signal formation unit which forms an image signal of the sample based on the acoustic signal; an information unit having information representing a relation between intensity of the pulse light entering the sample and intensity of the acoustic signal generated from the sample; and a pulse light intensity changing unit which changes intensity of the pulse light from the light source based on the information.

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 system and method for using a microscope to at least haptically observe a specimen in a fluid is provided. In one embodiment of the present invention, an audio frequency modulation sensing (AFMS) device is used to convert an optical signal from the specimen into an electrical signal. A haptic feedback device is then used to convert the electrical signal in at least vibrations, thereby providing a user with haptic feedback associated with the optical signal from the specimen. In another embodiment, a second electrical signal can be provided to a second haptic feedback (e.g., shaker, piezo electric, electric current inducing, etc.) device in the fluid, thereby allowing for bidirectional haptic feedback between the user and the specimen. In other embodiments, aural data can be extracted from the electrical signal and presented to the user either alone in in synchronization with video data (e.g., from a video camera).

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.

The invention relates to a device (1) and a corresponding method for mid-infrared microscopy and/or analysis, the device (1) comprising at least one radiation unit (10) configured to generate radiation (11) of time-varying intensity, the radiation (11) comprising one or more wavelengths in the mid-infrared spectral range, at least one refractive and/or reflective optical unit (12) which is configured to focus and/or direct the radiation (11) to at least one region or point of interest (20) located on and/or with-in an object (2), at least one detection unit (18) configured to detect ultrasound waves (17) emitted by the object (2) at the at least one region or point of interest (20) in response to an interaction of the radiation (11) with the object (2) and to generate according detection signals, and an evaluation unit (25) configured to derive infor-mation regarding at least one property of the object (2) from the detection signals and/or to generate a spatial and/or spatio-temporal distribution of the detection sig-nals or of information derived from the detection signals obtained for the at least one region or point of interest (20) located on and/or within the object (2).

A method of detecting sub-surface voids in a sample comprises positioning a probe adjacent to a first point on the sample, emitting an ultrasonic wave from the probe towards the sample, moving the probe towards the sample, measuring a shear force amplitude of a reflection of the ultrasonic wave at the probe as the probe moves towards the sample, creating an approach curve by plotting the measured shear force amplitude of the reflection of the ultrasonic wave as a function of a distance between the probe and the sample, and determining whether a sub-surface void exists at the first point on the sample based on a slope of the approach curve.

The present document relates to a heterodyne scanning probe microscopy (SPM) method for subsurface imaging, and includes: applying, using a transducer, an acoustic input signal to the sample, wherein the acoustic input signal has a frequency of at least 1 gigahertz; sensing an acoustic output signal using a probe, the probe including a cantilever and a probe tip, wherein the probe tip is in contact with the surface, wherein the acoustic output signal is representative of acoustic waves responsive to the acoustic input signal that are measurable at the surface; wherein the acoustic input signal is applied to the sample comprising a distinct pulse of acoustic energy followed by a relaxation period, wherein an acoustic power of the acoustic input signal during the pulse is at least twice as large as an acoustic power during the relaxation period. The present document further relates to a scanning probe microscopy method.