Patterned wafer inspection system using a non-vibrating contact potential difference sensor
AssigneeQcept Technologies, Inc.
InventorsMark A. Schulze, Jun Liu, Jeffrey Alan Hawthorne
Life of this patent
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Abstract
A method and system for inspecting a surface of a material having a repeating pattern of relative work function. The method and system processes sensor data to identify data characteristic of the repeating pattern, and the sensor data is then further processed to remove the data characteristic of the repeating data, leading to a characteristic of non-uniformities of the material surface.
Claims16
In a method of inspecting a surface of a material that contains a repeating pattern of relative work functions for detecting non-uniformities in the pattern, comprising the steps of:
- providing a surface of a material;
- providing a non-vibrating contact potential difference sensor having a sensor probe tip;
- positioning the sensor probe tip a fixed distance above the surface of the material;
- continuously moving the surface and non-vibrating contact potential difference sensor relative to one another so that the probe tip moves parallel to the surface of the material;
- generating non-vibrating contact potential sensor data arising from the continuous motion of the sensor probe tip relative to the surface of the material, the sensor data representative of changes in contact potential difference between the sensor probe tip and the surface of the material;
- the improvement characterized by the steps of processing the sensor data to provide relative contact potential difference values;
- identifying relative contact potential difference data characteristic of the repeating pattern;
- processing the relative contact potential difference data to reduce effects of data characteristic of the repeating pattern and providing resulting data;
- and processing the resulting data to identify work function non-uniformities that are not part of the repeating pattern.
A system for inspecting a material having a surface with a repeating pattern of relative work function thereon, comprising;
- a non-vibrating contact potential difference sensor having a sensor probe tip;
- a scanning assembly for continuously, laterally scanning the material relative to the sensor probe tip to provide sensor data representative of changes in contact potential difference values;
- a computer having a memory with executable computer software program for analysis of the sensor data to identify relative contact potential data characteristic of the repeating pattern and processing the data characteristic of the repeating pattern to reduce effects of data characteristic of the repeating pattern and identify work function non-uniformities which are not part of the repeating pattern.
Dependencies are inferred from the claim text.