Abstract: A process implementing steps for determining encroachment of a spacer structure in a semiconductor device having thick and thin spacer regions, including a transition region formed therebetween. The method steps comprise: obtaining a line width roughness (LWR) measurement at at least one location along each thick, thin and transition spacer regions; determining a threshold LWR measurement value based on the LWR measurements; defining a region of interest (ROI) and obtaining a further LWR measurement in the ROI; comparing the LWR measurement in the ROI against the threshold LWR measurement value; and, notifying a user that either encroachment of the spacer structure is present when the LWR measurement in the ROI is below the threshold LWR measurement value, or that no encroachment of the spacer structure is present when the LWR measurement in the ROI is above the threshold LWR measurement value.

Abstract: Optimizing a measurement system under test (MSUT) is disclosed. In one embodiment, a method includes selecting a first set of adjustable parameters of the MSUT that affect a quality metric for the MSUT, calculating the quality metric over a range of values of each adjustable parameter in the first set of adjustable parameters, generating a first multidimensional response space based on the calculating step, and determining which value of each adjustable parameter optimizes the quality metric based on the first multidimensional response space. The multidimensional response space may be stored for later recall for other optimization exercises.

Abstract: A method for accurately measuring feature sizes and quantifying the beam spot size in a CDSEM at real time is provided. The inventive method is based on a scanning microscope and it works on both conductive and non-conductive features. The measurement of conductive feature includes first providing a conductive feature on a surface of a substrate (the substrate maybe an insulator, a semiconductor or a material stack thereof). The conductive feature is then connected to ground and thereafter an electron beam probe raster scans the sample. When the electron beam probe hits the conductive feature the spot will have a negative potential. The potential difference between the spot and the ground will induce an electrical current flow. When the electrical beam is off the conductive feature, there will be no current flow. Therefore, by measuring the current response to the location of the beam spot, the dimension of the conductive feature can be derived.

Abstract: Methods, systems and program products are disclosed for determining whether a measurement system under test (MSUT) matches a fleet including at least one other measurement system. The invention implements realistic parameters for analyzing a matching problem including single tool precision, tool-to-tool non-linearities and tool-to-tool offsets. A bottom-line tool matching precision metric that combines these parameters into a single value is then implemented. The invention also includes methods for determining a root cause of a matching problem, and for determining a fleet measurement precision metric.

Abstract: A test method for measuring adsorbed molecular contamination uses a test structure that includes a substrate comprising a plurality of separated test sites having a plurality separate thicknesses having a base design thickness and a designed thickness interrelationship. The test structure is exposed to a molecular contaminant environment to provide an adsorbed molecular contaminant layer upon each of the plurality of separated test sites. The plurality of separated test sites with the adsorbed molecular contaminant layer thereon is measured. An appropriate algorithm that considers the designed thickness interrelationship is used to determine at least one of: (1) the base design thickness; and (2) a thickness of the adsorbed molecular contaminant layer.

Abstract: A method of preparing recipes for operating a metrology tool, each recipe including a set of instructions for measuring dimensions in a microelectronic feature. A database includes a plurality of known instructions with best known methods for measuring different feature dimensions by creating a summary of a recipes used by the tool, and adding categorization attributes to identify the summary for retrieval from the database. There is provided a desired recipe having instructions for measuring desired dimensions, including a summary of parameters relating to tool function for the feature dimension to be measured. The method includes comparing the instructions in the desired recipe with the instructions in the database, identifying differences therebetween, modifying the desired recipe instructions to conform to the database instructions, verifying the desired recipe prior to using the modified desired recipe by the tool, and using the desired recipe to execute a feature measurement on the tool.

Abstract: A method of identifying failures in a metrology tool system used to measure desired dimensions in microelectronic features. Each metrology tool in the system runs a plurality of recipes for measuring desired dimensions in microelectronic features, with each recipe comprising a set of instructions for measuring at least one dimension in a microelectronic feature. The system includes an error log having stored thereon failures in measurement of microelectronic feature dimensions.

Abstract: A process implementing steps for determining encroachment of a spacer structure in a semiconductor device having thick and thin spacer regions, including a transition region formed therebetween. The method steps comprise: obtaining a line width roughness (LWR) measurement at at least one location along each thick, thin and transition spacer regions; determining a threshold LWR measurement value based on the LWR measurements; defining a region of interest (ROI) and obtaining a further LWR measurement in the ROI; comparing the LWR measurement in the ROI against the threshold LWR measurement value; and, notifying a user that either encroachment of the spacer structure is present when the LWR measurement in the ROI is below the threshold LWR measurement value, or that no encroachment of the spacer structure is present when the LWR measurement in the ROI is above the threshold LWR measurement value.

Abstract: A method of identifying failures in a metrology tool system used to measure desired dimensions in microelectronic features. Each metrology tool in the system runs a plurality of recipes for measuring desired dimensions in microelectronic features, with each recipe comprising a set of instructions for measuring at least one dimension in a microelectronic feature. The system includes an error log having stored thereon failures in measurement of microelectronic feature dimensions.

Abstract: Prediction of a functional characteristic(s) and/or description of a physical characteristic(s) of structural features on a substrate is performed using a method where a combination of a weighting function(s) and a correlation function(s) is applied to feedback information from the structural feature. The combination of functions is preferably selected using a calibration database containing (A) information describing a functional performance characteristic of reference structural features, and/or (B) information describing a physical characteristic of reference structural features, and information describing feedback from the reference structural features as a function of position over such reference structural features.

Abstract: Prediction of a functional characteristic(s) and/or description of a physical characteristic(s) of structural features on a substrate is performed using a method where a combination of a weighting function(s) and a correlation function(s) is applied to feedback information from the structural feature. The combination of functions is preferably selected using a calibration database containing (A) information describing a functional performance characteristic of reference structural features, and/or (B) information describing a physical characteristic of reference structural features, and information describing feedback from the reference structural features as a function of position over such reference structural features.

Abstract: A wafer metrology structure for measuring both critical dimension features of multiple patterns of a semiconductor device and overlay measurements of one pattern with respect to another. The measurements are readable by a single, one-dimensional scan of a metrology system. The wafer metrology structure includes at least a first feature of a first dimension formed in a first level of the semiconductor device. The first dimension is identical to a first critical dimension of a pattern formed in the corresponding first level. A wafer metrology pattern according to the present invention also includes a second pattern of a second dimension formed in a second level of the semiconductor device. The second pattern includes an aperture superposed over the first feature. The aperture exposes at least the first feature having a critical dimension of the first pattern and thus enables a metrology system to directly measure the first feature through the aperture.

Abstract: A method determining the status of a feature (e.g., a semiconductor contact hole or trench) using a measurement imaging tool such as a scanning electron microscope (SEM). The method first assures that the waveform signal obtained from the SEM is reliable. A blanked beam signal, provided in saved images from the SEM, is the basis for a signal quality factor. This signal is provided in the waveform analyzed by the system. The method then analyzes all of the data between the edges of the feature and fits various functions to the data to determine which provides the best fit. Multiple linear regression and the r2 (quality of fit) factor, or some other type of correlation coefficient, are used to determine which function has the best fit. The feature is then characterized based on the particular function chosen and on the correlation factor obtained.

Abstract: A method for calculating and correcting an astigmatism error in a charged particle beam system. Images are collected during a single focus sweep of the charged particle beam system. Different orientations of image features, such as lines on a stigmation target, are analyzed. Optimum sharpness or best focus values are obtained as a function of the objective lens settings. Appropriate changes to the settings of the astigmatism correctors are computed by taking a linear combination of optimum sharpness values associated with the different orientations of image features. Proper settings of the objective lens and the astigmatism correctors result in focusing of the beam into a "small" spot. In a scanning electron microscope, for example, two sets of quadrupole compensation coils are typically used as astigmatism correctors.

Abstract: A method for monitoring a process in which a feature is formed on a substrate. A plurality of dimensions of the feature are measured using a tool. An edge width of the feature is calculated based on the plurality of dimensions. The edge width is used to determine whether the process is operating within a desired specification. The calculated edge width is compared to a baseline edge width measurement to determine a difference between them. The process is determined to be operating within the specification if the difference is less than a threshold value. If the difference is greater than or equal to the threshold value, the method determines whether the difference is caused by a change in resolution of the tool. A plurality of diagnostic measurements of the edge width may be performed. The tool is adjusted to have a respectively different focus for each respective one of the plurality of diagnostic measurements.