Wafer Backside Gas Flow to Prevent Arcing During Deposition

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Solution Overview

Problem

The semiconductor industry faces challenges in forming integrated circuits with high component density, particularly in magnetic tunnel junction (MTJ) memory cells, due to arcing issues during physical vapor deposition (PVD) and chemical vapor deposition (CVD) processes that lead to undesirable metal balls at the wafer edge regions.

Innovation Solution

The method involves blowing inert gases such as N2, He, or Ne to the back surface of the wafer during PVD or CVD processes to prevent arcing and reduce metal ball defects by increasing the breakdown voltage, thereby improving the deposition process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If high-voltage breakdown is used during PVD or CVD processes to deposit conductive layers, then deposition efficiency is improved, but electrical arcing occurs causing ball defects and pattern deformation

Engineering Contradiction:

Improvedeposition efficiencyVSAvoiddefect-free deposition

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent changes the physical-chemical parameters of the process gas by replacing conventional gases (Ar, H2, N2) with sulfur hexafluoride (SF6) or sulfur tetrafluoride (SF4). This parameter change increases the breakdown voltage of the process gas, which suppresses electrical arcing and ball defects while maintaining deposition efficiency. The sulfur-containing gases provide both high breakdown voltage characteristics and reactive species for effective film formation.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent introduces sulfur hexafluoride or sulfur tetrafluoride gas to create a chemically inert yet electrically stable atmosphere during deposition. These sulfur fluorides provide an inert environment that prevents unwanted chemical reactions while their high breakdown voltage characteristics suppress electrical arcing, thereby eliminating ball defects and ensuring uniform, defect-free conductive layer deposition.

Inventive Principle:

Principle #39Inert atmosphere (Inert environment)

2Ease of manufacture

If conventional process gases (Ar, H2, N2) are used during deposition, then deposition process is simple, but electrical arcing causes ball defects and device failure

Engineering Contradiction:

Improvedeposition process simplicityVSAvoidelectrical arcing and ball defects

Core Design Contradiction:

Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The patent modifies the chemical composition parameter of the process gas from conventional inert gases (Ar, H2, N2) to sulfur fluorides (SF6, SF4). This parameter change maintains process simplicity while fundamentally altering the electrical properties of the gas atmosphere to increase breakdown voltage and suppress harmful electrical arcing and ball defects.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent converts the potential harm of using reactive sulfur-containing gases into a benefit by selecting SF6 or SF4, which provide both high breakdown voltage for arc suppression and controlled reactivity for effective deposition. The sulfur fluorides transform the harmful electrical arcing issue into a beneficial process condition that eliminates defects while maintaining deposition quality.

Inventive Principle:

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

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 approach reduces arcing and metal ball defects, enhancing the quality and reliability of conductive layers in semiconductor devices like MRAM arrays by minimizing undesirable deposits.

Implementation Method 1

reduces electrical arcing and prevents the formation of ball defects by increasing the breakdown voltage

Methodology Applied

Scientific EffectElectrical breakdown: Avalanche Breakdown

Implementation Method 2

Physical Vapor Deposition (PVD) and Chemical Vapor Deposition (CVD) are widely used for deposition processes

Methodology Applied

Scientific EffectPhysical Vapor Deposition: Physical Vapour Deposition

Implementation Method 3

Physical Vapor Deposition (PVD) and Chemical Vapor Deposition (CVD) are widely used for deposition processes

Methodology Applied

Scientific EffectChemical Vapor Deposition: Chemical Vapour Deposition

Implementation Method 4

The PVD process or the CVD process may be accompanied by the generation of plasma

Methodology Applied

Scientific EffectPlasma: Plasma

Data Source

PatentUS12603265B2Method for improving deposition process

Publication Date: 2026.04.14 TAIWAN SEMICONDUCTOR MANUFACTURING CO LTD

AI summary

A method includes placing a wafer on a wafer holder, depositing a film on a front surface of the wafer, and blowing a gas through ports in a redistributor onto a back surface of the wafer at a same time the deposition is performed. The gas is selected from a group consisting of nitrogen (N2), He, Ne, and combinations thereof.