Abstract: Systems and methods for inspecting or characterizing samples, such as by characterizing patterned features or structures of the sample. In an aspect, the technology relates to a method for characterizing a patterned structure of a sample. The method includes directing a pump beam to a first position on a surface of the sample to induce a surface acoustic wave in the sample and directing a probe beam to a second position on the sample, where the probe beam is affected by the surface acoustic wave when the probe beam reflects from the surface of the sample. The method also includes detecting the reflected probe beam, analyzing the detected reflected probe beam to identify a frequency mode in the reflected probe beam, and based on the identified frequency mode, determining at least one of a width or a pitch of a patterned feature in the sample.

Abstract: An alignment or overlay target that has an optically opaque layer disposed between the top and bottom target structure is measured using opto-acoustic metrology. A classifier library is generated for classifying whether an opto-acoustic metrology signal is on or off the bottom structure. A target may be measured by acquiring opto-acoustic measurement data for the bottom structure of the target and determining a location of the bottom structure using opto-acoustic metrology data acquired from the different locations over the bottom structure and the classifier library. Locations for acquisition of the data may be based on classification results of each measurement and a search pattern. The top structure of the target may be optically imaged. The relative position of the top structure with respect to the bottom structure is determined using the opto-acoustically determined location of the bottom structure and the image of the top structure.

Abstract: Measuring or inspecting samples through non-destructive systems and methods. Multiple light pulses emitted from a light source. The light pulses are split into pump pulses and probe pulses. A first probe pulse reaches the surface of a sample after a first time duration after a first pump pulse reaches the surface. A second pump pulse reaches the surface after a time duration after the first probe pulse. When the second pump pulse reflects off the sample, the second pump pulse may be altered by an acoustic wave generated by the first probe pulse. The reflected second pump pulse may be analyzed to determine a characteristic of the sample.

Abstract: Systems and methods for inspecting or characterizing samples, such as by characterizing patterned features or structures of the sample. In an aspect, the technology relates to a method for characterizing a patterned structure of a sample. The method includes directing a pump beam to a first position on a surface of the sample to induce a surface acoustic wave in the sample and directing a probe beam to a second position on the sample, wherein the probe beam is affected by the surface acoustic wave when the probe beam reflects from the surface of the sample. The method also includes detecting the reflected probe beam, analyzing the detected reflected probe beam to identify a frequency mode in the reflected probe beam, and based on the identified frequency mode, determining at least one of a width or a pitch of a patterned feature in the sample.

Abstract: 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.

Abstract: 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.

Abstract: A system and method for identifying one or more characteristics of a structure formed into a substrate is herein disclosed. Surface and bulk acoustic waves are induced in the substrate and travel past a structure of interest where the acoustic waves are sensed. Information concerning one or more characteristics of the structure is encoded in the wave. The encoded information is assessed to determine the characteristic of interest.

Abstract: A system and method for identifying one or more characteristics of a structure formed into a substrate is herein disclosed. Surface and bulk acoustic waves are induced in the substrate and travel past a structure of interest where the acoustic waves are sensed. Information concerning one or more characteristics of the structure is encoded in the wave. The encoded information is assessed to determine the characteristic of interest.

Abstract: An automatically adjustable method for use in opto-acoustic metrology or other types of metrology operations is described. The method includes modifying the operation of a metrology system that uses a PSD style sensor arrangement. The method may be used to quickly adjust the operation of a metrology system to ensure that the data obtained therefrom are of the desired quality. Further, the method is useful in searching for and optimizing data that is or can be correlated to substrate or sample features or characteristics that of interest. Apparatus and computer readable media are also described.

Abstract: An automatically adjustable method for use in opto-acoustic metrology or other types of metrology operations is described. The method includes modifying the operation of a metrology system that uses a PSD style sensor arrangement. The method may be used to quickly adjust the operation of a metrology system to ensure that the data obtained therefrom are of the desired quality. Further, the method is useful in searching for and optimizing data that is or can be correlated to substrate or sample features or characteristics that of interest. Apparatus and computer readable media are also described.

Abstract: A method includes selecting one of performing ellipsometry or performing optical stress generation and detection. The method also includes, in response to selecting performing ellipsometry, applying at least one first control signal to a controllable retarder that modifies at least polarization of a light beam, and performing ellipsometry using the modified light beam. The method further includes, in response to selecting performing optical stress generation and detection, applying at least one second control signal to the controllable retarder, and performing optical stress generation and detection using the modified light beam. Apparatus and computer readable media are also disclosed.

Abstract: A method includes selecting one of performing ellipsometry or performing optical stress generation and detection. The method also includes, in response to selecting performing ellipsometry, applying at least one first control signal to a controllable retarder that modifies at least polarization of a light beam, and performing ellipsometry using the modified light beam. The method further includes, in response to selecting performing optical stress generation and detection, applying at least one second control signal to the controllable retarder, and performing optical stress generation and detection using the modified light beam. Apparatus and computer readable media are also disclosed.

Abstract: The present invention relates to a method for writing an optical structure within a workpiece of a dielectric material using FLDM. In a first embodiment system parameters for the FLDM are determined in dependence upon the dielectric material, a predetermined volume element and a predetermined change of the refractive index of the dielectric material within the predetermined volume element. The system parameters are determined such that self-focusing of a pulsed femtosecond laser beam is inhibted by non-linear absorption of the energy of the pulsed femtosecond laser beam within the dielectric material. A pulsed femtosecond laser beam based on the determined system parameters is focused at a predetermined location within the workpiece for inducing a change of the refractive index through dielectric modification within the predetermined volume element, the volume element including the focus. Various embodiments enable writing of various different optical structures into a workpiece.

Abstract: The present invention relates to a method for writing an optical structure within a workpiece of a dielectric material using FLDM. In a first embodiment system parameters for the FLDM are determined in dependence upon the dielectric material, a predetermined volume element and a predetermined change of the refractive index of the dielectric material within the predetermined volume element. The system parameters are determined such that self-focusing of a pulsed femtosecond laser beam is inhibted by non-linear absorption of the energy of the pulsed femtosecond laser beam within the dielectric material. A pulsed femtosecond laser beam based on the determined system parameters is focused at a predetermined location within the workpiece for inducing a change of the refractive index through dielectric modification within the predetermined volume element, the volume element including the focus. Various embodiments enable writing of various different optical structures into a workpiece.

Abstract: The present invention relates to a method for writing an optical structure within a workpiece of a dielectric material using FLDM. In a first embodiment system parameters for the FLDM are determined in dependence upon the dielectric material, a predetermined volume element and a predetermined change of the refractive index of the dielectric material within the predetermined volume element. The system parameters are determined such that self-focusing of a pulsed femtosecond laser beam is inhibted by non-linear absorption of the energy of the pulsed femtosecond laser beam within the dielectric material. A pulsed femtosecond laser beam based on the determined system parameters is focused at a predetermined location within the workpiece for inducing a change of the refractive index through dielectric modification within the predetermined volume element, the volume element including the focus. Various embodiments enable writing of various different optical structures into a workpiece.