Abstract: An apparatus for in-situ etching monitoring in a plasma processing chamber includes a continuous wave broadband light source, an illumination system configured to illuminate an area on a substrate with an incident light beam being directed from the continuous wave broadband light source at normal incidence to the substrate, a collection system configured to collect a reflected light beam being reflected from the illuminated area on the substrate, and to direct the reflected light beam to a first light detector, and a controller. The controller is configured to determine a property of the substrate or structures formed thereupon based on a reference light beam and the reflected light beam, and control an etch process based on the determined property. The reference light beam is generated by the illumination system by splitting a portion of the incident light beam and directed to a second light detector.

Abstract: An apparatus for in-situ etching monitoring in a plasma processing chamber includes a continuous wave broadband light source, an illumination system configured to illuminate an area on a substrate with an incident light beam being directed from the continuous wave broadband light source at normal incidence to the substrate, a collection system configured to collect a reflected light beam being reflected from the illuminated area on the substrate, and to direct the reflected light beam to a first light detector, and a controller. The controller is configured to determine a property of the substrate or structures formed thereupon based on a reference light beam and the reflected light beam, and control an etch process based on the determined property. The reference light beam is generated by the illumination system by splitting a portion of the incident light beam and directed to a second light detector.

Abstract: An apparatus, a system, and a method for in-situ etching monitoring in a plasma processing chamber are provided. The apparatus includes a continuous wave broadband light source to generate incident light beam, an illumination system configured to illuminate an area on a substrate with an incident light beam being directed at normal incidence to the substrate, a collection system configured to collect a reflected light beam being reflected from the illuminated area on the substrate, and direct the reflected light beam to a detector, and processing circuitry. The processing circuitry is configured to process the reflected light beam to suppress background light, determine a property of the substrate or structures formed thereupon based on reference light beam and the reflected light beam that are processed to suppress the background light, and control an etch process based on the determined property.

Abstract: An apparatus and a method for in-situ phase determination are provided. The apparatus includes a measurement chamber configured to retain a substance, and an entrance window mounted on a side of the measurement chamber. An exit window is mounted on an opposite side of the measurement chamber, and the exit window is parallel with the entrance window. The apparatus further includes a light source configured to generate an incident light beam. The incident light beam is directed to the entrance window at a non-zero angle of incidence with respect to a normal of the entrance window. The incident light beam passes through the entrance window, the measurement chamber and the exit window to form an output light beam. A detector is positioned under the exit window and configured to collect the output light beam passing through the exit window and generate measurement data.

Abstract: An apparatus, a system, and a method for in-situ etching monitoring in a plasma processing chamber are provided. The apparatus includes a continuous wave broadband light source to generate incident light beam, an illumination system configured to illuminate an area on a substrate with an incident light beam being directed at normal incidence to the substrate, a collection system configured to collect a reflected light beam being reflected from the illuminated area on the substrate, and direct the reflected light beam to a detector, and processing circuitry. The processing circuitry is configured to process the reflected light beam to suppress background light, determine a property of the substrate or structures formed thereupon based on reference light beam and the reflected light beam that are processed to suppress the background light, and control an etch process based on the determined property.

Abstract: An apparatus and a method for in-situ phase determination are provided. The apparatus includes a measurement chamber configured to retain a substance, and an entrance window mounted on a side of the measurement chamber. An exit window is mounted on an opposite side of the measurement chamber, and the exit window is parallel with the entrance window. The apparatus further includes a light source configured to generate an incident light beam. The incident light beam is directed to the entrance window at a non-zero angle of incidence with respect to a normal of the entrance window. The incident light beam passes through the entrance window, the measurement chamber and the exit window to form an output light beam. A detector is positioned under the exit window and configured to collect the output light beam passing through the exit window and generate measurement data.

Abstract: Disclosed is a method, computer method, system, and apparatus for measuring two-dimensional distributions of optical emissions from a plasma in a semiconductor plasma processing chamber. The acquired two-dimensional distributions of plasma optical emissions can be used to infer the two-dimensional distributions of concentrations of certain chemical species of interest that are present in the plasma, and thus provide a useful tool for process development and also for new and improved processing tool development. The disclosed technique is computationally simple and inexpensive, and involves the use of an expansion of the assumed optical intensity distribution into a sum of basis functions that allow for circumferential variation of optical intensity. An example of suitable basis functions are Zernike polynomials.

Abstract: A method for improving computation efficiency for diffraction signals in optical metrology is described. The method includes simulating a set of diffraction orders for a three-dimensional structure. The diffraction orders within the set of diffraction orders are then prioritized. The set of diffraction orders is truncated to provide a truncated set of diffraction orders based on the prioritizing. Finally, a simulated spectrum is provided based on the truncated set of diffraction orders.

Abstract: Provided are optimized scatterometry techniques for evaluating a diffracting structure. In one embodiment, a method includes computing a finite-difference derivative of a field matrix with respect to first parameters (including a geometric parameter of the diffracting structure), computing an analytic derivative of the Jones matrix with respect to the field matrix, computing a derivative of the Jones matrix with respect to the first parameters, and computing a finite-difference derivative of the Jones matrix with respect to second parameters (including a non-geometric parameter). In one embodiment, a method includes generating a transfer matrix having Taylor Series approximations for elements, and decomposing the field matrix into two or more smaller matrices based on symmetry between the incident light and the diffracting structure.

Abstract: Disclosed is an in-situ optical monitor (ISOM) system and associated method for controlling plasma etching processes during the forming of stepped structures in semiconductor manufacturing. The in-situ optical monitor (ISOM) can be optionally configured for coupling to a surface-wave plasma source (SWP), for example a radial line slotted antenna (RLSA) plasma source. A method is described to correlate the lateral recess of the steps and the etched thickness of a photoresist layer for use with the in-situ optical monitor (ISOM) during control of plasma etching processes in the forming of stepped structures.

Abstract: Disclosed is a method, computer method, system, and apparatus for measuring two-dimensional distributions of optical emissions from a plasma in a semiconductor plasma processing chamber. The acquired two-dimensional distributions of plasma optical emissions can be used to infer the two-dimensional distributions of concentrations of certain chemical species of interest that are present in the plasma, and thus provide a useful tool for process development and also for new and improved processing tool development. The disclosed technique is computationally simple and inexpensive, and involves the use of an expansion of the assumed optical intensity distribution into a sum of basis functions that allow for circumferential variation of optical intensity. An example of suitable basis functions are Zernike polynomials.

Abstract: Provided are techniques for numerically integrating an intensity distribution function over a numerical aperture in a manner dependent on a determination of whether the numerical aperture spans a Rayleigh singularity. Where a singularity exists, Gaussian quadrature (cubature) is performed using a set of weights and points (nodes) that account for the effect of the Wood anomaly present within the aperture space. The numerical aperture may be divided into subregions separated by curves where the Wood anomaly condition is satisfied. Each subregion is then numerically integrated and a weighted sum of the subregion contributions is the estimate of the integral. Alternatively, generalized Gaussian quadrature (cubature) is performed where an analytical polynomial function which accounts for the effect of the Wood anomaly present within the aperture space is integrated. Points and nodes generated from a fit of the analytical polynomial function are then used for integration of the intensity distribution function.

Abstract: Provided are techniques for numerically integrating an intensity distribution function over a numerical aperture in a manner dependent on a determination of whether the numerical aperture spans a Rayleigh singularity. Where a singularity exists, Gaussian quadrature (cubature) is performed using a set of weights and points (nodes) that account for the effect of the Wood anomaly present within the aperture space. The numerical aperture may be divided into subregions separated by curves where the Wood anomaly condition is satisfied. Each subregion is then numerically integrated and a weighted sum of the subregion contributions is the estimate of the integral. Alternatively, generalized Gaussian quadrature (cubature) is performed where an analytical polynomial function which accounts for the effect of the Wood anomaly present within the aperture space is integrated. Points and nodes generated from a fit of the analytical polynomial function are then used for integration of the intensity distribution function.

Abstract: Disclosed is an in-situ optical monitor (ISOM) system and associated method for controlling plasma etching processes during the forming of stepped structures in semiconductor manufacturing. The in-situ optical monitor (ISOM) can be optionally configured for coupling to a surface-wave plasma source (SWP), for example a radial line slotted antenna (RLSA) plasma source. A method is described to correlate the lateral recess of the steps and the etched thickness of a photoresist layer for use with the in-situ optical monitor (ISOM) during control of plasma etching processes in the forming of stepped structures.

Abstract: Methods and apparatuses for improving computation efficiency for diffraction signals in optical metrology are described. The method includes simulating a set of diffraction orders for a structure. A set of diffraction efficiencies is determined for the set of diffraction orders. A rational approximation or a continued-fraction approximation is applied to the set of diffraction efficiencies to obtain a rationally approximated set of diffraction efficiencies or a continued-fraction approximated set of diffraction efficiencies, respectively. A simulated spectrum is then provided.

Abstract: Provided are techniques for numerically integrating an intensity distribution function over a numerical aperture in a manner dependent on a determination of whether the numerical aperture spans a Rayleigh singularity. Where a singularity exists, Gaussian quadrature (cubature) is performed using a set of weights and points (nodes) that account for the effect of the Wood anomaly present within the aperture space. The numerical aperture may be divided into subregions separated by curves where the Wood anomaly condition is satisfied. Each subregion is then numerically integrated and a weighted sum of the subregion contributions is the estimate of the integral. Alternatively, generalized Gaussian quadrature (cubature) is performed where an analytical polynomial function which accounts for the effect of the Wood anomaly present within the aperture space is integrated. Points and nodes generated from a fit of the analytical polynomial function are then used for integration of the intensity distribution function.

Abstract: Provided are optimized scatterometry techniques for evaluating a diffracting structure. In one embodiment, a method includes computing a finite-difference derivative of a field matrix with respect to first parameters (including a geometric parameter of the diffracting structure), computing an analytic derivative of the Jones matrix with respect to the field matrix, computing a derivative of the Jones matrix with respect to the first parameters, and computing a finite-difference derivative of the Jones matrix with respect to second parameters (including a non-geometric parameter). In one embodiment, a method includes generating a transfer matrix having Taylor Series approximations for elements, and decomposing the field matrix into two or more smaller matrices based on symmetry between the incident light and the diffracting structure.

Abstract: A first wafer is fabricated using a first value for a process parameter specifying a process condition in fabricating the structure. A first value of a dispersion is measured from the first wafer. A second wafer is fabricated using a second value for the process parameter. A second value of the dispersion is measured from the second wafer. A third wafer is fabricated using a third value for the process parameter. The first, second, and third values for the process parameter are different from each other. A third value of the dispersion is measured from the third wafer. A dispersion function is defined to relate the process parameter to the dispersion using the first, second, and third values for the process parameter and the measured first, second, and third values of the dispersion. The simulated diffraction signal is generated using the defined dispersion function. The simulated diffraction signal is stored.

Abstract: An optical metrology model is created for a structure formed on a semiconductor wafer. The optical metrology model comprises one or more profile parameters, one or more process parameters, and dispersion. A dispersion function is obtained that relates the dispersion to at least one of the one or more process parameters. A simulated diffraction signal is generated using the optical metrology model and a value for the at least one of the process parameters and a value for the dispersion. The value for the dispersion is calculated using the value for the at least one of the process parameter and the dispersion function. A measured diffraction signal of the structure is obtained. The measured diffraction signal is compared to the simulated diffraction signal. One or more profile parameters of the structure and one or more process parameters are determined based on the comparison of the measured diffraction signal to the simulated diffraction signal.

Abstract: Methods and apparatuses for improving computation efficiency for diffraction signals in optical metrology are described. The method includes simulating a set of diffraction orders for a structure. A set of diffraction efficiencies is determined for the set of diffraction orders. A rational approximation or a continued-fraction approximation is applied to the set of diffraction efficiencies to obtain a rationally approximated set of diffraction efficiencies or a continued-fraction approximated set of diffraction efficiencies, respectively. A simulated spectrum is then provided.