Discrete Radiation Source Placement for IC Soft-Error Testing

Solution Overview

Problem

Conventional methods for testing integrated circuit chips for soft-error rates due to ionizing radiation expose all circuits simultaneously, making it difficult to determine the susceptibility of individual circuits to radiation.

Innovation Solution

A radiation-emitting layer is formed over selected or specific regions of an integrated circuit chip using a liquid mixture of a polymer or resin and a radioactive material, allowing for targeted exposure and measurement of soft-error rates in specific circuits.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a radiation source is placed between the integrated circuit chip and supporting module, then all circuits on the chip are exposed to radiation for testing, but it becomes difficult to determine the susceptibility of individual circuits to radiation

Engineering Contradiction:

Improvesoft-error rate testing capabilityVSAvoidindividual circuit susceptibility measurement

Core Design Contradiction:

ReliabilityVSMeasurement precision

Solution Approach 1:

The radiation-emitting layer is segmented into discrete regions, with each region positioned over a specific circuit or circuit block on the integrated circuit chip. This segmentation allows radiation to be emitted from multiple localized sources rather than a single broad source, enabling the testing of individual circuits or circuit blocks separately. Each discrete placement of radioactive material creates a focused radiation zone that targets specific circuits, thereby resolving the contradiction between comprehensive testing coverage and individual circuit measurement precision.

Inventive Principle:

Principle #1Segmentation

2Reliability

If the radiation-emitting layer covers the entire top surface of the integrated circuit chip, then all circuits are exposed to radiation, but the ability to measure soft-error rates of specific individual circuits is lost

Engineering Contradiction:

Improvecomprehensive radiation exposureVSAvoidindividual circuit soft-error rate measurement

Core Design Contradiction:

ReliabilityVSMeasurement precision

Solution Approach 1:

The radiation-emitting layer exhibits local quality by having different spatial distributions of radioactive material corresponding to different circuits or circuit blocks. Each local region of the layer contains radioactive material in concentrations and configurations tailored to the specific testing requirements of the underlying circuit. This local differentiation allows simultaneous comprehensive coverage while maintaining the ability to measure individual circuit susceptibility, as each circuit receives radiation from its own dedicated region of the layer.

Inventive Principle:

Principle #3Local quality

3Ease of manufacture

If conventional testing methods are used with a single radiation source, then the testing process is simple, but it cannot determine which specific circuits are susceptible to radiation

Engineering Contradiction:

Improvetesting process simplicityVSAvoidcircuit-specific soft-error rate determination

Core Design Contradiction:

Ease of manufactureVSMeasurement precision

Solution Approach 1:

The radiation-emitting layer is segmented into discrete regions, with each region positioned over a specific circuit or circuit block on the integrated circuit chip. This segmentation allows radiation to be emitted from multiple localized sources rather than a single broad source, enabling the testing of individual circuits or circuit blocks separately. Each discrete placement of radioactive material creates a focused radiation zone that targets specific circuits, thereby resolving the contradiction between comprehensive testing coverage and individual circuit measurement precision.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The radiation-emitting layer serves as an intermediary structure that bridges the gap between simple radiation sources and complex individual circuit testing requirements. By incorporating multiple discrete radioactive material placements within a single layer, the intermediary structure maintains ease of manufacture (as it is still a single layer applied to the chip) while enabling precise individual circuit measurement through its segmented radiation emission pattern.

Inventive Principle:

Principle #24Intermediary (Mediator)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach enables precise determination of soft-error rates in individual circuits, allowing for tailored adjustments to their operation and improving the reliability of integrated circuit devices.

Implementation Method 1

a radioactive material formed over the function circuit, the radiation emitting-layer smaller than a whole of the top surface of the integrated circuit chip, the functional circuit liable to temporary failure when struck by radiation generated by the radioactive material

Methodology Applied

Scientific EffectRadioactive decay: Radioactive Decay

Data Source

PatentUS7649257B2Discrete placement of radiation sources on integrated circuit devices

Publication Date: 2010.01.19 GLOBALFOUNDRIES US INC

AI summary

An integrated circuit and methods of forming and using the integrated circuit. The circuit includes: a radiation-emitting layer over a selected region of a top surface of an integrated circuit chip, the radiation emitting layer comprising a first polymer or resin and a first radioactive material, the region smaller than a whole of the top surface of the integrated circuit chip, the region including a circuit that is liable to temporary failure when struck by radiation generated by the first radioactive material.