Oxide Semiconductor Structure With Edge Nitrogen for Stable Reliability

Solution Overview

Problem

Semiconductor devices using oxide semiconductors face reliability issues due to oxygen vacancies and defects in the insulating layer, leading to abnormal characteristics and fluctuations in performance, which are challenging to address with existing methods that either result in high defect insulating layers or insufficient oxygen supply.

Innovation Solution

A semiconductor device structure incorporating a nitrogen-containing region with a nitrogen composition ratio of 2% or more within 2 nanometers from the surface of the oxide semiconductor layer, introduced through plasma treatment, to improve reliability by reducing defects and enhancing oxygen supply.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If an insulating layer with large amount of oxygen is used to supply oxygen to oxide semiconductor, then oxygen supply is improved, but defect concentration increases causing abnormal characteristics and reliability issues

Engineering Contradiction:

Improveoxygen content in insulating layerVSAvoiddevice reliability

Core Design Contradiction:

Quantity of substanceVSReliability

Solution Approach 1:

The patent applies local quality by creating a nitrogen-containing region specifically at the edge portion of the oxide semiconductor layer adjacent to the insulating layer, rather than uniformly distributing nitrogen throughout. This localized nitrogen introduction (with composition ratio of 1×10^19 to 1×10^21 atoms/cm³) occurs only in the region where oxygen supply from the insulating layer happens, allowing this specific area to have enhanced oxygen stability while the rest of the device maintains optimal characteristics without excessive nitrogen contamination.

Inventive Principle:

Principle #3Local quality

2Reliability

If an insulating layer with less defects is used to improve device characteristics, then defect concentration is reduced, but oxygen supply capability decreases

Engineering Contradiction:

Improvedevice characteristics stabilityVSAvoidoxygen content in insulating layer

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

The patent applies preliminary action by introducing nitrogen into the oxide semiconductor layer before the insulating layer is formed or during subsequent processing steps. This pre-treatment ensures that when the insulating layer (which may be oxygen-rich) is later formed or when oxygen diffusion occurs, the nitrogen-containing region is already in place to stabilize oxygen and prevent vacancy formation, proactively preventing reliability issues before they occur.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent uses nitrogen as an intermediary substance that mediates between the oxygen supply from the insulating layer and the oxide semiconductor layer. The nitrogen atoms, introduced at specific concentrations in the edge portion of the oxide semiconductor, act as intermediaries that stabilize oxygen atoms, preventing them from forming vacancies while still allowing the insulating layer to serve its oxygen supply function effectively.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Reliability

If nitrogen is introduced into oxide semiconductor layer to improve reliability, then oxygen stability is enhanced, but manufacturing complexity increases

Engineering Contradiction:

Improveoxygen vacancy reductionVSAvoidmanufacturing process complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies local quality by creating a nitrogen-containing region specifically at the edge portion of the oxide semiconductor layer adjacent to the insulating layer, rather than uniformly distributing nitrogen throughout. This localized nitrogen introduction (with composition ratio of 1×10^19 to 1×10^21 atoms/cm³) occurs only in the region where oxygen supply from the insulating layer happens, allowing this specific area to have enhanced oxygen stability while the rest of the device maintains optimal characteristics without excessive nitrogen contamination.

Inventive Principle:

Principle #3Local quality

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

The nitrogen-containing region effectively improves the reliability of the semiconductor device by reducing defects and maintaining stable performance, as evidenced by improved reliability test results and simulation models.

Implementation Method 1

The oxide semiconductor layer includes a region in which a composition ratio of nitrogen is 2 percent or more within a depth range of 2 nanometers from the first surface in a region vicinity of an edge of at least one of the first electrode of the pair of first electrode

Methodology Applied

Scientific EffectNitrogen incorporation:

Implementation Method 2

introduced through plasma treatment

Methodology Applied

Scientific EffectPlasma treatment: Plasma

Data Source

PatentUS20230387322A1Semiconductor device

Publication Date: 2023.11.30 MAGNOLIA WHITE CORP

AI summary

A semiconductor device including: an oxide semiconductor layer including a first surface and a second surface opposite to the first surface; a gate electrode facing the oxide semiconductor layer; a gate insulating layer between the oxide semiconductor layer and the gate electrode; and a pair of first electrode being in contact with the first surface of the oxide semiconductor layer, respectively, wherein the oxide semiconductor layer including a region in which composition ratio of nitrogen is 2 percent or more within a depth range of 2 nanometers from the first surface in a region vicinity of an edge of at least one of the first electrode of the pair of first electrode.