Abstract: A method for estimating a state of a process implemented by a tool for fabricating workpieces includes collecting metrology data associated with a subset of workpieces processed in the tool. The collecting exhibits an irregular pattern. Metrology data associated with a selected state observation is received for a selected run of the process. A tuning factor for the selected run is determined based on the irregular pattern. The selected state observation is discounted based on the determined tuning factor. A state estimate of the process is determined based on the discounted selected state observation. At least one process tool operable to implement the process is controlled based on the state estimate.

Abstract: A method for estimating a state of a process implemented by a tool for fabricating workpieces includes collecting metrology data associated with a subset of workpieces processed in the tool. The collecting exhibits an irregular pattern. Metrology data associated with a selected state observation is received for a selected run of the process. A tuning factor for the selected run is determined based on the irregular pattern. The selected state observation is discounted based on the determined tuning factor. A state estimate of the process is determined based on the discounted selected state observation. At least one process tool operable to implement the process is controlled based on the state estimate.

Abstract: A test structure includes a first plurality of lines and a second plurality of lines intersecting the first plurality of lines. The first and second pluralities of lines defining a grid having openings. A method for determining grid dimensions includes providing a wafer having a test structure comprising a plurality of intersecting lines that define a grid having openings; illuminating at least a portion of the grid with a light source; measuring light reflected from the illuminated portion of the grid to generate a reflection profile; and determining a dimension of the grid based on the reflection profile. A metrology tool is adapted to receive a wafer having a test structure comprising a plurality of intersecting lines that define a grid having openings. The metrology tool includes a light source, a detector, and a data processing unit. The light source is adapted to illuminate at least a portion of the grid.

Abstract: A method includes defining a design window for a manufacturing process performed by a tool and a process window within the design window. A workpiece likely to have a characteristic outside the process window is identified. The characteristic of the identified workpiece is measured. A control model for controlling the tool is updated using the measured characteristic. A system includes a tool, a process controller, a metrology tool, and a sampling controller. The tool is adapted to process workpieces in accordance with a manufacturing process. The manufacturing process has an associated design window and a process window defined within the design window. The process controller is adapted to control the tool using a control model. The sampling controller is adapted to identify a workpiece likely to have a characteristic outside the process window and direct the metrology tool to measure the characteristic of the identified workpiece.

Abstract: A test structure includes a plurality of lines and a plurality of contact openings defined in the lines. A method for determining contact opening dimensions includes providing a wafer having a test structure comprising a plurality of lines and a plurality of contact openings defined in the lines; illuminating at least a portion of the contact openings with a light source; measuring light reflected from the illuminated portion of the contact openings to generate a reflection profile; and determining a dimension of the contact openings based on the reflection profile. A metrology tool adapted to receive a wafer having a test structure comprising a plurality of lines and a plurality of contact openings defined in the lines includes a light source, a detector, and a data processing unit. The light source is adapted to illuminate at least a portion of the contact openings. The detector is adapted to measure light reflected from the illuminated portion of the contact openings to generate a reflection profile.

Abstract: A test structure includes a plurality of trenches and a plurality of columns defined in the trenches. A method for determining column dimensions includes providing a wafer having a test structure comprising a plurality of trenches and a plurality of columns defined in the trenches; illuminating at least a portion of the columns with a light source; measuring light reflected from the illuminated portion of the columns to generate a reflection profile; and determining a dimension of the columns based on the reflection profile. A metrology tool adapted to receive a wafer having a test structure comprising a plurality of trenches and a plurality of columns defined in the trenches includes a light source, a detector, and a data processing unit. The light source is adapted to illuminate at least a portion of the columns. The detector is adapted to measure light reflected from the illuminated portion of the columns to generate a reflection profile.