Semiconductor Degradation Measurement Using Paired Ring Oscillators

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing semiconductor degradation measurement techniques face challenges in accurately measuring aged-degradation due to voltage and temperature variations, as well as errors caused by differences in power-source impedances and potential errors between power supplies, making real-time measurement of degradation levels difficult.

Innovation Solution

A semiconductor apparatus with a paired-oscillators configuration, including an operation ring oscillator and a reference ring oscillator, connected in series and parallel with switches to control power supply and prevent degradation, allowing for accurate comparison of pulse counts to determine degradation levels by using a common power supply and minimizing measurement errors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a reference ring oscillator is used to measure aged-degradation by comparing pulse counts with a test ring oscillator, then degradation measurement is enabled, but measurement errors occur due to voltage fluctuations and power-source impedance differences

Engineering Contradiction:

Improveaged-degradation measurement precisionVSAvoidmeasurement reliability

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The patent connects both the test ring oscillator and reference ring oscillator to the same power supply terminal, ensuring they operate at the same potential level. This eliminates measurement errors caused by potential differences between separate power supplies and ensures that voltage fluctuations affect both oscillators equally, allowing accurate degradation measurement through comparison.

Inventive Principle:

Principle #12Equipotentiality

Solution Approach 2:

The patent merges the power supply connections by connecting both oscillators to a common power supply terminal rather than using separate power supplies. This combination eliminates the harmful effects of power-source impedance differences and potential errors between independent power supplies, improving measurement reliability.

Inventive Principle:

Principle #5Merging (Combining)

2Productivity

If the reference ring oscillator operates continuously to provide reference pulses, then real-time measurement is enabled, but the reference oscillator deteriorates over time due to continuous operation

Engineering Contradiction:

Improvereal-time measurement capabilityVSAvoidreference oscillator stability

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent implements periodic action by controlling the reference ring oscillator to operate only during measurement periods rather than continuously. The control circuit activates the reference oscillator simultaneously with the test oscillator during designated measurement windows, allowing real-time degradation assessment while minimizing the reference oscillator's operational time and associated deterioration.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The patent applies preliminary action by pre-controlling the operation timing of the reference oscillator through a control circuit that activates it only when needed for measurement. This preliminary control prevents unnecessary operation and degradation of the reference oscillator while ensuring it is ready for simultaneous operation with the test oscillator when measurement is required.

Inventive Principle:

Principle #10Preliminary action

3Adaptability or versatility

If separate power supplies are used for test and reference ring oscillators, then independent control is possible, but errors occur due to differences in power-source impedances and potential errors

Engineering Contradiction:

Improveindependent control flexibilityVSAvoiddegradation measurement accuracy

Core Design Contradiction:

Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The patent eliminates separate power supplies by connecting both the test ring oscillator and reference ring oscillator to the same power supply terminal. This creates equipotential operating conditions for both oscillators, eliminating measurement errors caused by potential differences and power-source impedance variations between independent power supplies, thereby improving degradation measurement accuracy.

Inventive Principle:

Principle #12Equipotentiality

Data Source

PatentUS10461721B2Semiconductor apparatus, degradation value determination system and processing system

Publication Date: 2019.10.29 RENESAS ELECTRONICS CORP

AI summary

A semiconductor apparatus includes an operation oscillator, a reference oscillator, a first operation switch connected in series with the operation oscillator between a power supply potential VDD and a ground potential GND, a first reference switch connected in series with the reference oscillator between the power supply potential VDD and the ground potential GND, a second reference switch connected in parallel with the reference oscillator between the power supply potential VDD and the ground potential GND, an operation counter configured to count the number of output pulses from the operation oscillator in a measurement period, and a reference counter configured to count the number of output pulses from the reference oscillator in the measurement period.