Guard Ring Conductive Layer Width for Moisture Protection

Solution Overview

Problem

In semiconductor devices formed through divided exposure, position displacement between guard ring patterns due to overlay errors in mask alignment can create gaps between the patterns, allowing moisture to enter the element formation region and reduce circuit reliability.

Innovation Solution

A semiconductor device design with a guard ring conductive layer that is wider than the interconnection conductive layer, ensuring that even with position displacement between divided exposure patterns, the guard ring patterns remain connected without gaps, thereby preventing moisture ingress.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If divided exposure is used to form a chip region larger than the exposure range, then the chip size can be increased, but position displacement between patterns occurs due to overlay errors of masks

Engineering Contradiction:

Improvechip region sizeVSAvoidpattern position accuracy

Core Design Contradiction:

Area of stationary objectVSManufacturing precision

Solution Approach 1:

A guard ring structure is introduced as an intermediary element between the element formation region and the external environment. This guard ring acts as a barrier that compensates for the position displacement caused by overlay errors in divided exposure, preventing moisture ingress while allowing the chip region to be formed through divided exposure processes.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The guard ring is designed with sufficient width beforehand to cushion or absorb the potential position displacement that will occur during divided exposure. By pre-establishing this protective structure with adequate dimensions, the patent ensures that even when overlay errors occur, the guard ring patterns remain connected and continue to function as a moisture barrier.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

2Area of stationary object

If the guard ring pattern width is reduced to minimize area, then the chip area is optimized, but gaps may form between divided patterns due to overlay errors

Engineering Contradiction:

Improveguard ring areaVSAvoidmoisture protection reliability

Core Design Contradiction:

Area of stationary objectVSReliability

Solution Approach 1:

The patent optimizes the width parameter of the guard ring pattern to a specific range that balances area minimization with gap prevention. By carefully selecting the guard ring width parameter, the design achieves compact area while ensuring that the patterns remain connected despite overlay errors during divided exposure.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The guard ring is designed with sufficient width beforehand to cushion or absorb the potential position displacement that will occur during divided exposure. By pre-establishing this protective structure with adequate dimensions, the patent ensures that even when overlay errors occur, the guard ring patterns remain connected and continue to function as a moisture barrier.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

3Productivity

If divided exposure is performed for the guard ring region, then manufacturing efficiency is improved, but overlay errors cause gaps between patterns at boundary portions

Engineering Contradiction:

Improvemanufacturing efficiencyVSAvoidpattern connection accuracy

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The guard ring structure serves as an intermediary that decouples the productivity benefit of divided exposure from the precision requirement of pattern connection. By introducing this protective structure, the patent allows divided exposure to be used for efficiency while the guard ring itself compensates for the precision loss from overlay errors.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The guard ring is designed with sufficient width beforehand to cushion or absorb the potential position displacement that will occur during divided exposure. By pre-establishing this protective structure with adequate dimensions, the patent ensures that even when overlay errors occur, the guard ring patterns remain connected and continue to function as a moisture barrier.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

Data Source

PatentUS9691719B2Semiconductor device

Publication Date: 2017.06.27 RENESAS ELECTRONICS CORP

AI summary

A semiconductor device is a semiconductor device in which one chip region is formed through divided exposure. An interlayer insulating film has a via and an interconnection trench in an element formation region and has a guard ring hole in a guard ring region. An interconnection conductive layer is formed in the via and the interconnection trench. A guard ring conductive layer is formed in the guard ring hole. A minimum dimension of a width of the guard ring conductive layer is greater than a minimum dimension of a width of the interconnection conductive layer in the via.