Complementary ring oscillators to monitor in-situ stress within integrated circuits
US11719584B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 18, 2021 |
| Grant date | Aug 8, 2023 |
| Priority date | — |
| Expiry date | Sep 30, 2041 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R31/2884
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The disclosure relates to technology for determining stress on integrated circuits. These include using ring oscillators formed on the integrated circuit, where one ring oscillator has its frequency dependent on the current flowing through its stages being limited by its NMOS devices and another ring oscillator has its frequency dependent on the current flowing through its stages being limited by its PMOS devices. This allows the stress on the integrated circuit to be determined in different directions along the integrated circuit. A temperature sensor can be used to compensate for temperature dependence on the frequencies of the ring oscillators.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.