Sputtering Target Aperture for Backing Plate Exposure Detection

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Solution Overview

Problem

Sputtering target assemblies cannot promptly detect the exposure of the backing plate, leading to contamination of the substrate with backing plate material and inefficient utilization of the target material due to inability to halt the sputtering process in time.

Innovation Solution

A sputtering target assembly with apertures in the backing plate positioned at predicted high etching rates, sealed by the target, which releases a gas or fluid when exposed, triggering an alarm to halt the sputtering process and prevent contamination.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of substance

If the sputtering process continues without detection mechanism, then the target material can be fully utilized, but the backing plate becomes exposed and contaminates the substrate

Engineering Contradiction:

Improvetarget material utilization efficiencyVSAvoidsubstrate contamination

Core Design Contradiction:

Loss of substanceVSObject-affected harmful factors

Solution Approach 1:

The patent positions apertures in the backing plate at locations predicted to experience highest etching rates based on sputtering target erosion profiles. This preliminary positioning ensures that the apertures are strategically placed to detect exposure at the critical moment before substrate contamination occurs, allowing the system to take preventive action

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent implements a feedback mechanism where the release of gas or fluid from exposed apertures triggers an alarm system that halts the sputtering process. This closed-loop feedback enables real-time monitoring and automatic response to prevent backing plate material from contaminating the substrate while maximizing target material utilization

Inventive Principle:

Principle #23Feedback

2Measurement precision

If apertures are positioned at predicted high etching rate locations, then detection accuracy is improved, but device complexity increases

Engineering Contradiction:

Improveexposure detection accuracyVSAvoidaperture positioning complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent applies local quality by positioning apertures at specific locations on the backing plate where highest etching rates are predicted to occur, rather than uniformly distributing them. This localized approach concentrates detection capability at the most critical areas, improving detection accuracy without requiring apertures throughout the entire backing plate structure

Inventive Principle:

Principle #3Local quality

3Object-affected harmful factors

If the sputtering process is halted immediately upon exposure detection, then substrate contamination is prevented, but target material utilization becomes inefficient

Engineering Contradiction:

Improvesubstrate contamination preventionVSAvoidtarget material utilization efficiency

Core Design Contradiction:

Object-affected harmful factorsVSLoss of substance

Solution Approach 1:

The feedback mechanism triggers the alarm and process halt only when the aperture becomes exposed and releases gas or fluid, which occurs at the precise moment of target depletion. This timing allows maximum utilization of the target material while preventing any backing plate material from reaching the substrate, as the halt occurs before contamination can occur

Inventive Principle:

Principle #23Feedback

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

Prevents contamination of the substrate by stopping the sputtering process before the backing plate material is sputtered and optimizes target material utilization by detecting fluctuations in pressure or voltage, ensuring efficient film deposition.

Implementation Method 1

Sputter deposition is a physical vapor deposition (PVD) method that is used to form thin films by ejecting material from a target or source material onto a substrate

Methodology Applied

Scientific EffectSputtering: Sputtering

Implementation Method 2

The aperture may be disposed at a location that is predicted by a sputtering target erosion profile to have the highest etching rate during a corresponding sputtering process. As the sputtering process erodes the target plate, the aperture in the backing plate may be exposed releasing a gas/fluid contained therein

Methodology Applied

Scientific EffectPressure gradient: Pressure Gradient

Data Source

PatentUS11557470B2Sputtering target assembly to prevent overetch of backing plate and methods of using the same

Publication Date: 2023.01.17 TAIWAN SEMICONDUCTOR MANUFACTURING CO LTD

AI summary

A sputtering target assembly, sputtering apparatus, and method, the target assembly including a backing plate having an aperture formed therein; and a target bonded to a front surface of the backing plate. The aperture is disposed on the backing plate such that a first end of the aperture is sealed by a portion of the target that is predicted by a sputtering target erosion profile to have the highest etching rate during a corresponding sputtering process.