Load-Lock Shield Layout for Gate-Valve Particle Isolation

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Solution Overview

Problem

The transfer of wafer substrates between high and low pressure environments in semiconductor manufacturing, particularly in EUV photolithography, is prone to particle contamination due to wear at the gate valve seal and seat, leading to reduced wafer yield and increased maintenance time.

Innovation Solution

Incorporating one or more protective shields within the load-lock chamber to block particles generated during gate valve operation, ensuring the shields do not contact any objects and thus do not generate additional particles, while the gate valves maintain a gas-tight seal.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If gate valves are used to transfer wafers between pressure environments, then wafer transfer is enabled, but particle contamination occurs due to wear at the gate valve seal and seat

Engineering Contradiction:

Improvewafer transfer capabilityVSAvoidparticle contamination

Core Design Contradiction:

Ease of operationVSObject-affected harmful factors

Solution Approach 1:

A protective shield is introduced as an intermediary component between the gate valve and the wafer. The shield blocks particles generated during gate valve operation from contaminating the wafer, while allowing the gate valve to continue its sealing function. The shield is positioned to intercept particles before they can reach the wafer surface.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The load-lock chamber is segmented into distinct zones: a gate valve zone where particles are generated, and a wafer zone protected from particles. The protective shield creates a physical separation between these zones, allowing the gate valve to operate independently without directly contaminating the wafer environment.

Inventive Principle:

Principle #1Segmentation

2Reliability

If gate valve seal and seat wear occurs, then particle contamination increases, but maintenance time and downtime increase

Engineering Contradiction:

Improvewafer yieldVSAvoidmaintenance downtime

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The protective shield is installed beforehand to cushion or intercept particles before they can contaminate the wafer. This preventive measure reduces the severity and frequency of contamination events, thereby reducing the need for frequent maintenance and minimizing downtime.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

3Object-affected harmful factors

If protective shields are added to block particles, then wafer yield improves, but device complexity increases

Engineering Contradiction:

Improveparticle contamination reductionVSAvoidshield mechanism complexity

Core Design Contradiction:

Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The protective shield is designed as a simple, easily replaceable component. Rather than creating a complex active system, the solution uses a straightforward shield structure that can be quickly installed and replaced if needed, minimizing the overall complexity of the system while effectively reducing particle contamination.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

Data Source

PatentUS20240006202A1Apparatuses and methods for reducing particle contamination of wafers during transfer

Publication Date: 2024.01.04 TAIWAN SEMICONDUCTOR MANUFACTURING CO LTD

AI summary

A load-lock chamber with reduced particle contamination is disclosed. At least one movable particle shield is placed between the gate valve and a wafer location. Particles which can be generated due to contact between the gate valve door and its seat are blocked or inhibited by the particle shield from landing in the wafer location, reducing particle contamination. Methods for operating the load-lock chamber are also disclosed.