Semiconductor Guard Ring Spacing for Plasma Damage Reduction

Solution Overview

Problem

The reliability of semiconductor devices is compromised due to the risk of static electricity and plasma-induced breakdowns, particularly when forming openings during the production process, as existing guard rings can act as antennas and are susceptible to charge-up during dry etching.

Innovation Solution

The semiconductor device design incorporates a guard ring configuration where the distance between the opening and the ring is greater than the distance between the opening and the isolation region, and the use of wet etching to form openings, which reduces the impact of static electricity and plasma damage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a guard ring is formed in the vicinity of the recess inside the stacked wiring portion to prevent peeling of the insulating film, then the bonding strength is improved, but the reliability deteriorates due to susceptibility to static electricity and plasma-induced breakdowns

Engineering Contradiction:

Improvebonding strengthVSAvoidreliability

Core Design Contradiction:

StrengthVSReliability

Solution Approach 1:

The device is divided into functional regions: a pixel region containing photodiodes and a peripheral region containing the guard ring. This segmentation allows the guard ring to be positioned away from sensitive elements, reducing static electricity impact while maintaining its peeling prevention function.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The guard ring is positioned in the peripheral region at a distance from the pixel region, utilizing spatial arrangement in the planar dimension. This dimensional positioning reduces the guard ring's exposure to plasma and static electricity during opening formation while maintaining its structural support function for preventing insulating film peeling.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Manufacturing precision

If dry etching is used to form openings, then manufacturing precision is improved, but the reliability deteriorates due to charge-up and plasma damage to the semiconductor layer and guard ring

Engineering Contradiction:

Improveopening formation precisionVSAvoidreliability

Core Design Contradiction:

Manufacturing precisionVSReliability

Solution Approach 1:

An inert gas atmosphere is introduced as an intermediary environment during the opening formation process. This inert atmosphere suppresses plasma-induced charge-up and damage to the semiconductor layer and guard ring, allowing precise opening formation while protecting sensitive structures.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The opening formation process is conducted in an inert gas atmosphere that prevents plasma from causing charge-up and damage. This inert environment protects the semiconductor layer and guard ring during etching, maintaining reliability while achieving precise opening formation.

Inventive Principle:

Principle #39Inert atmosphere (Inert environment)

3Strength

If the guard ring is disposed close to the opening, then the bonding strength is improved, but the risk of breakdown increases due to static electricity influence

Engineering Contradiction:

Improvebonding strengthVSAvoidstatic electricity impact

Core Design Contradiction:

StrengthVSObject-affected harmful factors

Solution Approach 1:

The device is divided into functional regions: a pixel region containing photodiodes and a peripheral region containing the guard ring. This segmentation allows the guard ring to be positioned away from sensitive elements, reducing static electricity impact while maintaining its peeling prevention function.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The guard ring is positioned in the peripheral region at a distance from the pixel region, utilizing spatial arrangement in the planar dimension. This dimensional positioning reduces the guard ring's exposure to plasma and static electricity during opening formation while maintaining its structural support function for preventing insulating film peeling.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

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 configuration enhances the reliability of the semiconductor device by minimizing the risk of breakdowns and improving the bonding strength, leading to better image quality and measurement accuracy when used in applications such as transportation apparatuses.

Implementation Method 1

the opening is formed by wet etching the semiconductor layer

Methodology Applied

Scientific EffectWet etching:

Data Source

PatentUS11276723B2Semiconductor device, apparatus, and method for producing semiconductor device

Publication Date: 2022.03.15 CANON KK

AI summary

A semiconductor device comprising: a substrate; a semiconductor layer; and a wiring structure section between the substrate and the semiconductor layer, the wiring structure section including a plurality of stacked wiring layers and a plurality of stacked insulating films, the wiring structure section including an electrode, wherein an opening for connecting a member to the electrode is formed in the semiconductor layer and the wiring structure section; the semiconductor layer has an isolation region in which an insulating film is embedded and which surrounds the opening; the wiring structure section has a ring which is formed of the plurality of wiring layers and surround the opening; and a distance between the opening and the ring closest to the opening is larger than a distance between the opening and the isolation region closest to the opening.