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US 10,770,327 B2Granted
System and method for correcting non-ideal wafer topography
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsCheng-Mu Lin, Chi-Hung Liao, Yi-Ming Dai, Yueh Lin Yang
Life of this patent
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Abstract
A scanner includes a light source configured to apply a light to a backside of a wafer. The light is reflected from the backside of the wafer. A first mirror is configured to receive the light from the backside of the wafer and reflect the light. A sensor is configured to receive the light from the first mirror and generate an output signal indicative of a backside topography of the wafer.
Claims20
A scanner comprising:
- a light source configured to apply a light to a backside of a wafer at a first adjustable incident angle with respect to a first horizontal axis;
- a first mirror positioned to receive light reflected from a backside of a wafer when the light source is applied to the backside of the wafer and reflect the light, wherein a change in the first adjustable incident angle of ΔΘ corresponds to a horizontal movement of the first mirror Δx on a second horizontal axis parallel to the first horizontal axis;
- and
- a sensor positioned to receive light reflected from the first mirror when the light source is applied to the backside of the wafer, wherein the sensor is configured to generate an output signal indicative of a backside topography of the wafer.
1 more element
A method, comprising:
- applying a light from a light source to a first portion of a backside of a wafer at a first incident angle, wherein the backside of the wafer reflects the light;
- reflecting the light applied at the first incident angle from the backside of the wafer to a sensor;
- applying the light from the light source to a second portion of the backside of the wafer at a second incident angle;
- reflecting the light applied at the second incident angle from the backside of the wafer to the sensor;
- generating, by the sensor, a signal indicative of a backside topography of the wafer;
- and
- generating a corrected overlay map based on the signal indicative of the backside topography of the wafer.
4 more elements
A system, comprising:
- a backside scanner comprising:
- a light source configured to apply a light to a semiconductor wafer at a first adjustable incident angle with respect to a first horizontal axis;
- a first mirror positioned to receive light reflected from the semiconductor wafer when the light source is applied to the semiconductor wafer and reflect the light, wherein a change in the first adjustable incident angle of ΔΘ corresponds to a horizontal movement of the first mirror Δx on a second horizontal axis parallel to the first horizontal axis;
- and
- a sensor positioned to receive the light reflected from the first mirror when the light source is applied to the semiconductr wafer and generate an output signal indicative of a topography of the wafer;
- a wafer table comprising a plurality of wafer supports extending from a top surface of the wafer table, wherein each of the plurality of wafer supports has a predetermined spacing and a predetermined height, and wherein the predetermined spacing, the predetermined height, or both of each the plurality of wafer supports has a variable value;
- a processor configured to receive the output signal from the sensor and generate a corrected overlay map, wherein the corrected overlay map is configured to compensate for the variable value of each of the plurality of wafer supports;
- and
- a semiconductor manufacturing system configured to form at least one layer of a semiconductor device on a semiconductor wafer coupled to the wafer table, wherein the corrected overlay map is configured to compensate for topography of the semiconductor wafer.
6 more elements
Dependencies are inferred from the claim text.