Ring oscillator with embedded scatterometry grate array
First Claim
1. A ring oscillator comprising:
- a number of serially connected inverter stages, each stage including a p-channel transistor serially connected with an n-channel transistor; and
wherein at least one of the transistors comprises a scatterometry grate array.
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Accused Products
Abstract
A MOS ring oscillator includes a number of serially connected inverter stages with each stage comprising a MOS transistor pair. At least one of the transistors also comprises a scatterometry grate array, which is used during manufacturing of the ring oscillator to obtain scatterometry measurements that allow polysilicon lines of the MOS ring oscillator to have widths of less than 60 nm. A method includes forming at least one grate array above a substrate, illuminating the grate array, measuring light reflected off of the grate array to generate an optical characteristic trace for the grate array, and comparing the generated optical characteristic trace to a target optical characteristic trace that corresponds to a grate array having a desired profile. The generated trace can further be used to calibrate the ring oscillator
15 Citations
20 Claims
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1. A ring oscillator comprising:
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a number of serially connected inverter stages, each stage including a p-channel transistor serially connected with an n-channel transistor; and
wherein at least one of the transistors comprises a scatterometry grate array. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A method, comprising:
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forming at least one grate array above a substrate, wherein the grate array forms part of a transistor of a ring oscillator;
illuminating the grate array;
measuring light reflected off of the grate array to generate an optical characteristic trace for the grate array;
comparing the generated optical characteristic trace to a target optical characteristic trace that corresponds to a grate array having a desired surface profile; and
controlling a process for forming the grate array based upon the comparison of the generated trace and the target trace. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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Specification