Method and apparatus for determining a sampling plan based on process and equipment state information

A processing line, comprising:

• an etch tool configured to etch process layers;
• a metrology tool configured to measure an output characteristic of selected etched process layers in accordance with a sampling plan;
• a tool state monitor configured to observe at least one tool state variable value during the etching of a particular process layer in the etch tool;
• and
• a sampling controller configured to receive the observed tool state variable value and determine the sampling plan for the metrology tool based on the observed tool state variable value.

A method for processing workpieces, comprising:

• processing a plurality of workpieces in a processing tool;
• measuring a characteristic of selected workpieces in accordance with a sampling plan;
• observing at least one tool state variable value during the processing of a particular workpiece in the processing tool;
• and
• determining the sampling plan based on the observed tool state variable value.

A method for processing wafers, comprising:

• etching a plurality of process layers;
• measuring an output characteristic of the etched process layers in accordance with a sampling plan;
• observing at least one tool state variable value during the etching of a particular process layer;
• and
• determining the sampling plan based on the observed tool state variable value.

A processing line, comprising:

• means for processing a plurality of workpieces;
• means for measuring a characteristic of selected workpieces in accordance with a sampling plan;
• means for observing at least one tool state variable value during the processing of a particular workpiece;
• and
• means for determining the sampling plan based on the observed tool state variable value.

A processing line, comprising:

• means for etching process layers;
• means for measuring an output characteristic of the etched process layers in accordance with a sampling plan;
• means for observing at least one tool state variable value during the etching of a particular process layer;
• and
• means for determining the sampling plan based on the observed tool state variable value.