Ceiling Plate Recessed Structures for MOCVD Epitaxial Growth

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Solution Overview

Problem

The MOCVD process for forming epitaxial films on wafers results in residual deposits on the reaction chamber's inner wall and gas nozzle, which can contaminate the wafers and cause defects, leading to reduced production yield and the need for frequent equipment shutdowns for cleaning.

Innovation Solution

The epitaxial growth device features a ceiling plate with a plurality of recessed structures that reduce the friction resistance of the reaction gas, minimizing the adhesion and subsequent peeling off of residual deposits, thereby reducing contamination of the wafers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a smooth ceiling plate is used in the MOCVD reactor, then the gas flow is smooth and the equipment is easy to clean, but residual deposits easily adhere to the ceiling and can peel off to contaminate wafers

Engineering Contradiction:

Improveease of cleaningVSAvoiddeposit adhesion and peeling

Core Design Contradiction:

Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The ceiling plate is designed with different surface properties in different regions: the central region has a rough surface to prevent deposit adhesion, while the peripheral region maintains a smooth surface for ease of cleaning. This local differentiation resolves the contradiction between preventing deposit adhesion and maintaining ease of cleaning.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The ceiling plate surface is segmented into multiple zones with different roughness characteristics. The rough central region and smooth peripheral region are clearly divided, allowing each zone to perform its specific function independently - the rough zone prevents deposit adhesion while the smooth zone facilitates cleaning operations.

Inventive Principle:

Principle #1Segmentation

2Productivity

If the MOCVD equipment operates continuously without shutdown, then production capacity is maintained, but residual deposits accumulate and cause wafer defects

Engineering Contradiction:

Improveproduction capacityVSAvoidwafer quality

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The rough surface structure is pre-designed on the ceiling plate to proactively prevent deposit adhesion before it occurs. This preliminary structural preparation eliminates the need for shutdowns to remove deposits, allowing continuous operation while maintaining wafer quality.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The invention converts the harmful effect of deposit accumulation into a beneficial outcome by designing a rough surface that prevents deposits from adhering in the first place. The rough texture creates a surface where deposits cannot stick, transforming the problem of deposit management into a solution that enables continuous production.

Inventive Principle:

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

3Object-affected harmful factors

If the ceiling plate has a rough surface to reduce deposit adhesion, then wafer contamination is reduced, but the surface area increases friction resistance to gas flow

Engineering Contradiction:

Improvewafer contaminationVSAvoidgas flow friction

Core Design Contradiction:

Object-affected harmful factorsVSLoss of energy

Solution Approach 1:

The ceiling plate implements local quality by providing rough surface characteristics only in the central region where deposit adhesion is problematic, while maintaining smooth surfaces in peripheral areas. This localized roughness reduces overall friction resistance compared to a completely rough surface, while still preventing wafer contamination effectively.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

Instead of making the entire ceiling plate rough, the invention applies roughness partially only to the central region where it is most needed for preventing deposit adhesion. This partial application minimizes the impact on gas flow friction while achieving the contamination prevention goal.

Inventive Principle:

Principle #16Partial or excessive 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

The use of recessed structures on the ceiling plate effectively reduces the occurrence of defects on the wafers by minimizing residual deposits, enhancing the quality of epitaxial films, and increasing production efficiency by reducing the need for frequent equipment shutdowns for cleaning.

Implementation Method 1

The ceiling plate includes a plurality of recessed structures so that when the reaction gas flows through the recessed structures, the friction resistance with the surface of the ceiling plate is reduced

Methodology Applied

Scientific EffectFriction resistance reduction through recessed structures: Friction

Data Source

PatentUS20250129510A1Ceiling plate and epitaxial growth device having the same

Publication Date: 2025.04.24 TAIWAN ASIA SEMICONDUCTOR CORPORATION

AI summary

A ceiling plate and an epitaxial growth device having the same are provided. The epitaxial growth device includes a wafer carrying platform and a reaction chamber. The wafer carrying platform is used to carry at least one wafer, and the reaction chamber accommodates the wafer carrying platform and includes a ceiling plate and a gas supply device. The ceiling plate is disposed on the top of the reaction chamber, and the gas supply device provides a reaction gas to at least one wafer on the wafer carrying platform. The ceiling plate includes a plurality of recessed structures so that when the reaction gas flows through the recessed structures, the friction resistance with the surface of the ceiling plate is reduced.