Flexible wafer leveling design for various orientation of line/trench
First Claim
1. A photolithography system, comprising:
- a lithographic exposure element configured to selectively expose a semiconductor substrate to electromagnetic radiation;
a level sensor configured to measure a height of a semiconductor substrate at different points over a top surface of the semiconductor substrate, comprising;
a projection source configured to generate a measurement beam that is provided to a semiconductor substrate via a projection grating;
a detector configured to receive a measurement beam that is reflected off of the semiconductor substrate via a detection grating and to measure an intensity of the measurement beam corresponding to a height of the semiconductor substrate; and
an ambulatory element configured to selectively adjust an orientation of the detection grating or the projection grating, wherein the ambulatory element is configured to compare the intensity of the measurement beam to a threshold value and to adjust an orientation of the detection grating or the projection grating if the intensity violates the threshold value.
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Accused Products
Abstract
The present disclosure relates to a photolithography system having an ambulatory projection and/or detection gratings that provide for high quality height measurements without the use of an air gauge. In some embodiments, the photolithography system has a level sensor having a projection source that generates a measurement beam that is provided to a semiconductor substrate via a projection grating. A detector is positioned to receive a measurement beam reflected from the semiconductor substrate via a detection grating. An ambulatory element selectively varies an orientation of the projection grating and/or the detection grating to improve the measurement of the level sensor. By selectively varying an orientation of the projection and/or detection gratings, erroneous measurements of the level sensor can be eliminated.
8 Citations
20 Claims
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1. A photolithography system, comprising:
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a lithographic exposure element configured to selectively expose a semiconductor substrate to electromagnetic radiation; a level sensor configured to measure a height of a semiconductor substrate at different points over a top surface of the semiconductor substrate, comprising; a projection source configured to generate a measurement beam that is provided to a semiconductor substrate via a projection grating; a detector configured to receive a measurement beam that is reflected off of the semiconductor substrate via a detection grating and to measure an intensity of the measurement beam corresponding to a height of the semiconductor substrate; and an ambulatory element configured to selectively adjust an orientation of the detection grating or the projection grating, wherein the ambulatory element is configured to compare the intensity of the measurement beam to a threshold value and to adjust an orientation of the detection grating or the projection grating if the intensity violates the threshold value. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A level sensor configured to measure a height of a semiconductor substrate at different points over a top surface of the semiconductor substrate, comprising:
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a projection source configured to generate a measurement beam that is reflected off of a semiconductor substrate; a detector configured to receive the measurement beam reflected off of the semiconductor substrate and to measure an intensity of the measurement beam; a detection grating positioned between the semiconductor substrate and the detector; a projection grating positioned between the projection source and the semiconductor substrate; and an ambulatory element-configured to selectively rotate the detection grating or the projection grating if the intensity violates a threshold value. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16, 17)
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18. A method of determining a height of a semiconductor substrate for a photolithography process, comprising:
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providing a semiconductor substrate into a photolithography tool with an ambulatory projection grating or an ambulatory detection grating; operating a level sensor to generate a measurement beam along a path that passes through the projection grating or the detection grating; measuring an intensity level of the measurement beam passing through the detection grating; selectively adjusting an orientation of the projection grating or the detection grating based upon the intensity level; and comparing the intensity level to a threshold value, wherein if the intensity level violates the threshold value the orientation of the projection grating or the detection grating is adjusted. - View Dependent Claims (19, 20)
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Specification