Multi-Cathode PVD Process Kit Shielding for Cross-Contamination

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Solution Overview

Problem

In multi-cathode PVD chambers, cross-contamination between targets occurs due to the deposition of material on chamber components outside the processing volume, leading to inconsistencies in film deposition during semiconductor fabrication.

Innovation Solution

A process kit for a multi-cathode processing chamber comprising a rotatable shield, shrouds, conical shield, inner and outer deposition rings, and a cover ring, which minimizes cross-contamination by selectively exposing targets and capturing target flux, thereby reducing material deposition on chamber components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple targets are used in a multi-cathode PVD chamber to deposit different materials, then material diversity and film composition flexibility are improved, but cross-contamination between targets occurs leading to film consistency deterioration

Engineering Contradiction:

Improvematerial diversityVSAvoidfilm consistency

Core Design Contradiction:

Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The processing chamber is segmented into multiple isolated cathode regions, each with its own target. Physical barriers such as shutters and deposition shields divide the chamber space to prevent material from one cathode from contaminating other cathodes, allowing multiple materials to be processed simultaneously without cross-contamination

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Deposition shields and shutter mechanisms act as intermediary elements between the cathodes and substrate. These intermediaries selectively block or direct material flux, ensuring that only the intended target material deposits on the substrate while preventing cross-contamination from other targets

Inventive Principle:

Principle #24Intermediary (Mediator)

2Manufacturing precision

If targets are cleaned periodically to maintain film consistency, then film quality is improved, but particle generation occurs during the cleaning process

Engineering Contradiction:

Improvefilm qualityVSAvoidparticle generation

Core Design Contradiction:

Manufacturing precisionVSObject-generated harmful factors

Solution Approach 1:

The cleaning process is extracted and isolated to specific maintenance periods when the chamber is not in production mode. During normal operation, deposition shields prevent material accumulation on chamber components, reducing the frequency and intensity of cleaning operations required and thereby minimizing particle generation events

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

Deposition shields are positioned beforehand to intercept and capture sputtered material before it can deposit on chamber components. This preemptive protection reduces the amount of material that would otherwise require removal during cleaning, thereby reducing particle generation during necessary maintenance operations

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

3Quantity of substance

If chamber components are exposed to target flux, then material deposition on components occurs, but this leads to cross-contamination and requires frequent cleaning

Engineering Contradiction:

Improvematerial depositionVSAvoidcleaning frequency

Core Design Contradiction:

Quantity of substanceVSLoss of time

Solution Approach 1:

Deposition shields serve as intermediary components that deliberately intercept target flux before it can reach other chamber components. These shields are designed to be easily replaceable and are positioned to protect critical components, thereby reducing the frequency of cleaning operations and associated production losses

Inventive Principle:

Principle #24Intermediary (Mediator)

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 process kit effectively minimizes cross-contamination and ensures consistent film deposition by isolating targets and directing material flux towards the substrate, reducing contamination and improving defect performance.

Implementation Method 1

Physical vapor deposition (PVD) in semiconductor fabrication is typically performed with a target made of a desired film material

Methodology Applied

Scientific EffectPhysical Vapour Deposition: Physical Vapour Deposition

Implementation Method 2

In the case of alloys, the targets are typically composed of the alloy to be sputtered

Methodology Applied

Scientific EffectSputtering: Sputtering

Data Source

PatentEP3635767B1Process kit for multi-cathode processing chamber

Publication Date: 2022.10.26 APPLIED MATERIALS INC

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AI summary

Process kits for use in a multi-cathode process chamber are disclosed. Process kits include one or more of a conical shield, rotatable shield, shroud, inner deposition ring, outer deposition ring, or a cover ring. In some embodiments, a process kit includes: a rotatable shield having a base, a conical portion extending downward and outward therefrom, and a collar portion extending outward from the conical portion; an inner deposition ring having a leg portion, a flat portion extending inward from the leg portion, a first recessed portion extending inward from the flat portion, and a first lip extending upward from an innermost section of the first recessed portion; and an outer deposition ring having a collar portion, an upper flat portion above and extending inwardly from the collar portion, a second recessed portion extending inwardly from the upper flat portion, and a second lip extending upwardly from the second recessed portion.