Patent application number | Description | Published |
20080212080 | MEASURING A PROCESS PARAMETER OF A SEMICONDUCTOR FABRICATION PROCESS USING OPTICAL METROLOGY - To measure a process parameter of a semiconductor fabrication process, the fabrication process is performed on a first area using a first value of the process parameter. The fabrication process is performed on a second area using a second value of the process parameter. A first measurement of the first area is obtained using an optical metrology tool. A second measurement of the second area is obtained using the optical metrology tool. One or more optical properties of the first area are determined based on the first measurement. One or more optical properties of the second area are determined based on the second measurement. The fabrication process is performed on a third area. A third measurement of the third area is obtained using the optical metrology tool. A third value of the process parameter is determined based on the third measurement and a relationship between the determined optical properties of the first and second areas. | 09-04-2008 |
20080231863 | Automated process control using optical metrology with a photonic nanojet - A fabrication cluster can be controlled using optical metrology. A fabrication process is performed on a wafer using a fabrication cluster. A photonic nanojet, an optical intensity pattern induced at a shadow-side surface of a dielectric microsphere, is generated. An inspection area on the wafer is scanned with the photonic nanojet. A measurement is obtained of the retroreflected light from the dielectric microsphere as the photonic nanojet scans the inspection area. The existence of a structure in the inspection area is determined with the obtained measurement of the retroreflected light. One or more process parameters of the fabrication cluster is adjusted based on the determination of the existence of the structure in the inspection area. | 09-25-2008 |
20090076782 | GENERATING SIMULATED DIFFRACTION SIGNAL USING A DISPERSION FUNCTION RELATING PROCESS PARAMETER TO DISPERSION - 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. | 03-19-2009 |
20090082993 | AUTOMATED PROCESS CONTROL OF A FABRICATION TOOL USING A DISPERSION FUNCTION RELATING PROCESS PARAMETER TO DISPERSION - An optical metrology model for the structure is obtained. The optical metrology model comprising one or more profile parameters, one or more process parameters, and a dispersion. A dispersion function that relates the dispersion to at least one of the one or more process parameters is obtained. 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 using an optical metrology tool. The measured diffraction signal is compared to the simulated diffraction signal to determine one or more profile parameters of the structure. The fabrication tool is controlled based on the determined one or more profile parameters of the structure. | 03-26-2009 |
20090083013 | DETERMINING PROFILE PARAMETERS OF A STRUCTURE FORMED ON A SEMICONDUCTOR WAFER USING A DISPERSION FUNCTION RELATING PROCESS PARAMETER TO DISPERSION - 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. | 03-26-2009 |
20100042388 | COMPUTATION EFFICIENCY BY DIFFRACTION ORDER TRUNCATION - 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. | 02-18-2010 |
20100145655 | RATIONAL APPROXIMATION AND CONTINUED-FRACTION APPROXIMATION APPROACHES FOR COMPUTATION EFFICIENCY OF DIFFRACTION SIGNALS - 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. | 06-10-2010 |
20130211760 | NUMERICAL APERTURE INTEGRATION FOR OPTICAL CRITICAL DIMENSION (OCD) METROLOGY - 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. | 08-15-2013 |
20140024143 | SYSTEM FOR IN-SITU FILM STACK MEASUREMENT DURING ETCHING AND ETCH CONTROL METHOD - 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. | 01-23-2014 |