Semiconductor Contact Structure With Barrier Layer for Oxide-Safe Cleaning

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Solution Overview

Problem

The existing manufacturing processes for semiconductor devices face challenges in effectively removing natural oxide films from polycrystalline silicon semiconductor layers without etching oxide semiconductor layers, particularly when using cleaning agents like hydrofluoric acid, which can damage the oxide semiconductor layers.

Innovation Solution

A semiconductor device structure and manufacturing method that incorporates a conductive barrier layer to protect the oxide semiconductor layer during cleaning, allowing for the removal of natural oxide films from polycrystalline silicon semiconductor layers while preventing etching of the oxide layer, thereby reducing manufacturing steps and maintaining reliability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If cleaning liquid such as hydrofluoric acid is used to remove natural oxide film from polycrystalline silicon semiconductor layer, then the oxide film removal is effective, but the oxide semiconductor layer is etched and damaged

Engineering Contradiction:

Improveoxide film removal effectivenessVSAvoidetching damage to oxide semiconductor layer

Core Design Contradiction:

Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

A barrier layer is introduced as an intermediary between the cleaning liquid and the oxide semiconductor layer. This barrier layer selectively protects the oxide semiconductor layer from etching by hydrofluoric acid while allowing the natural oxide film on the polycrystalline silicon layer to be removed. The barrier layer acts as a mediator that enables the cleaning process to proceed without damaging the sensitive oxide semiconductor layer.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The barrier layer is formed only in specific regions where oxide semiconductor layers are located, providing localized protection. This allows different regions of the substrate to have different properties: regions with oxide semiconductor layers are protected from etching, while regions with polycrystalline silicon layers can undergo effective oxide film removal. The selective formation of the barrier layer enables differentiated treatment of different semiconductor layers.

Inventive Principle:

Principle #3Local quality

2Object-affected harmful factors

If additional protective layers are added to prevent etching of oxide semiconductor layer, then the oxide layer is protected, but the manufacturing process complexity increases

Engineering Contradiction:

Improveprotection of oxide semiconductor layerVSAvoidmanufacturing process steps

Core Design Contradiction:

Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The barrier layer formation process is merged with existing manufacturing processes. The barrier layer is formed using the same sputtering equipment and process conditions as other conductive layers in the device, combining multiple functions into a single process step. This integration reduces the overall manufacturing complexity while still providing the necessary protection.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The barrier layer serves multiple functions: it acts as a protective layer during cleaning, serves as a conductive layer in the final device structure, and can be formed using standard sputtering processes already available in the manufacturing line. This multi-functionality reduces the need for additional specialized process steps.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Ease of manufacture

If conventional cleaning process is used without protective measures, then the manufacturing process is simple, but the oxide semiconductor layer reliability decreases

Engineering Contradiction:

Improvecleaning process simplicityVSAvoidoxide semiconductor layer integrity

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The barrier layer is formed in advance before the cleaning process that removes natural oxide films. This preliminary protective action ensures that the oxide semiconductor layer is protected during subsequent cleaning steps. The barrier layer is prepared beforehand, allowing the cleaning process to proceed with confidence that the oxide semiconductor layer will not be damaged.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS11855103B2Semiconductor device and method for manufacturing semiconductor device

Publication Date: 2023.12.26 MAGNOLIA WHITE CORP

AI summary

According to one embodiment, a semiconductor device includes an insulating substrate, a first semiconductor layer located above the insulating substrate, a second semiconductor layer located above the insulating substrate, an insulating layer which covers the first semiconductor layer and the second semiconductor layer, and includes a first contact hole reaching the first semiconductor layer and a second contact hole reaching the second semiconductor layer, a barrier layer which covers one of the first semiconductor layer inside the first contact hole and the second semiconductor layer inside the second contact hole, and a first conductive layer which is in contact with the barrier layer.