Semiconductor Oxide Cap Structure for Dopant Retention During Annealing

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

During thermal annealing of semiconductor materials, dopant ions escape due to heat, affecting the material's performance and polluting the process environment.

Innovation Solution

A forming method for a semiconductor structure involves placing a target structure in a reaction chamber and forming a first oxide layer on its surface, followed by the formation of a second oxide layer underneath, with the first oxide layer having a thinner thickness than the second oxide layer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If thermal annealing is performed to activate dopant ions, then the dopant ions can provide carriers in the semiconductor material, but some dopant ions escape from the semiconductor material due to heat

Engineering Contradiction:

Improveactivation of dopant ionsVSAvoidescape of dopant ions

Core Design Contradiction:

ReliabilityVSLoss of substance

Solution Approach 1:

A cap structure is formed on the semiconductor material before thermal annealing to prevent dopant ion escape during the subsequent heating process. This preliminary protective action ensures that when thermal annealing is performed to activate dopant ions, the cap structure prevents them from escaping due to heat, thus resolving the contradiction between activating dopants and preventing their loss.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The cap structure acts as an intermediary layer between the semiconductor material and the external environment during thermal annealing. It mediates the process by allowing heat to penetrate for dopant activation while simultaneously blocking the escape path of dopant ions, thus enabling both dopant activation and prevention of dopant loss.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If thermal annealing is performed to activate dopant ions, then the dopant ions can provide carriers in the semiconductor material, but the escaping dopant ions pollute the process environment

Engineering Contradiction:

Improveactivation of dopant ionsVSAvoidpollution of process environment

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The cap structure, which may be a waste or byproduct structure from previous fabrication steps, is repurposed as a protective barrier during thermal annealing. By converting this existing structure into a useful protective element, the solution prevents dopant ion escape and environmental pollution while maintaining the beneficial effect of dopant activation.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The cap structure serves as an intermediary that isolates the semiconductor material from the process environment during thermal annealing. It allows the necessary heat transfer for dopant activation while preventing harmful dopant ion escape into the environment, thus eliminating pollution while maintaining activation efficacy.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Loss of substance

If a single thick oxide layer is formed to prevent dopant ion escape, then dopant retention is improved, but the formation process becomes more complex and time-consuming

Engineering Contradiction:

Improveretention of dopant ionsVSAvoidcomplexity of oxide layer formation

Core Design Contradiction:

Loss of substanceVSDevice complexity

Solution Approach 1:

Instead of forming a single thick oxide layer, the solution segments the protective structure into a cap structure formed in multiple thinner layers or stages. This segmentation reduces the complexity of each individual formation step while achieving the same overall protective effect, thus preventing dopant ion escape without excessive process complexity.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The cap structure is formed preliminarily before thermal annealing in a controlled manner, potentially using existing fabrication processes. This preliminary formation approach simplifies the overall process by preparing the protective structure in advance rather than requiring complex real-time adjustments during annealing, thus reducing process complexity while ensuring dopant retention.

Inventive Principle:

Principle #10Preliminary action

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 method effectively reduces the escape of dopant ions and maintains their concentration within the semiconductor structure, enhancing its electrical performance and preventing environmental contamination.

Implementation Method 1

forming a first oxide layer on the target structure, where the first oxide layer has a first thickness; and forming a second oxide layer under the first oxide layer, where the second oxide layer has a second thickness

Methodology Applied

Scientific EffectOxidation: Oxidation

Data Source

PatentUS12341073B2Forming method of semiconductor structure and semiconductor structure

Publication Date: 2025.06.24 CHANGXIN MEMORY TECH INC

AI summary

The present disclosure relates to the technical field of semiconductors, and provides a forming method of a semiconductor structure and a semiconductor structure. The forming method of a semiconductor structure includes: placing a target structure in a reaction chamber; forming a first oxide layer on the target structure, where the first oxide layer has a first thickness; and forming a second oxide layer under the first oxide layer, where the second oxide layer has a second thickness, and the first thickness is less than the second thickness.