Room-Temperature Bonding Device Sputtering Impurity Control

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Solution Overview

Problem

Current room-temperature bonding techniques face challenges in preventing metal impurity adhesion during substrate bonding, which can lead to manufacturing line pollution and reduced bonding strength due to the difficulty in independently controlling intermediate layer formation and etching.

Innovation Solution

A room-temperature bonding apparatus and method that employs a covering member and target holding mechanism to minimize sputtering particle adhesion, using materials with low argon sputtering yields and non-obstructive properties to form intermediate layers without compromising device functionality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a particle beam is irradiated to form an intermediate layer on substrate surfaces, then bonding strength between substrates is improved, but metal impurities may adhere to substrates and pollute the manufacturing line

Engineering Contradiction:
Improvebonding strengthVSAvoidmetal impurity adhesion
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

A covering member made of material difficult to be sputtered (such as quartz or ceramic) is introduced as an intermediary between the particle beam and the substrates. This covering member selectively blocks metal impurities generated during sputtering while allowing the particle beam to pass through and form the intermediate layer on substrates, thus resolving the contradiction between achieving strong bonding and preventing contamination

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The vacuum chamber is segmented into multiple regions: a sputtering region where the intermediate layer is formed, and a substrate holding region where substrates are positioned. The covering member is disposed to separate these regions, allowing the particle beam to traverse from the sputtering region through the covering member to the substrate holding region, thereby preventing metal impurity adhesion while maintaining bonding strength

Inventive Principle:
Principle #1Segmentation

2Strength

If the bonding surfaces are activated by physical sputtering, then bonding strength is enhanced, but members in the vacuum chamber may be sputtered and adhere to substrates as impurities

Engineering Contradiction:
Improvebonding strengthVSAvoidsputtering particle adhesion
Core Design Contradiction:
StrengthVSObject-generated harmful factors

Solution Approach 1:

The covering member acts as a protective intermediary that blocks sputtering particles generated from vacuum chamber members while allowing the particle beam to pass through. This enables surface activation of bonding surfaces without the harmful side effect of metal impurity adhesion from chamber walls

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The harmful sputtering function is extracted from the vacuum chamber members by introducing the covering member. The covering member is specifically chosen to be difficult to sputter, effectively removing the source of metal impurities while preserving the necessary sputtering function for intermediate layer formation and surface activation

Inventive Principle:
Principle #2Taking out (Extraction)

3Adaptability or versatility

If multiple targets are sputtered to form intermediate layers of different materials, then bonding capability between different substrate materials is improved, but control precision of intermediate layer formation and etching becomes difficult

Engineering Contradiction:
Improvebonding capability between different materialsVSAvoidcontrol precision of intermediate layer formation
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The sputtering process is segmented into multiple sequential steps, with each step dedicated to forming a specific intermediate layer or performing etching. The particle beam is directed to different targets in sequence, allowing precise control over the composition and thickness of each intermediate layer while maintaining the ability to bond different substrate materials

Inventive Principle:
Principle #1Segmentation

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 effectively reduces impurity adhesion, enhances manufacturing yield and reliability, and minimizes the risk of manufacturing line pollution by independently controlling intermediate layer formation and etching, ensuring strong and reliable substrate bonding.

Implementation Method 1

a beam source irradiating an activation beam to bonding surfaces of the substrates; through a balance of a sputtering operation of the substrate surface with the inactive gas ion beam or the inactive gas neuter atom beam and a deposition operation of metal atoms

Methodology Applied
Scientific EffectPhysical sputtering: Sputtering

Implementation Method 2

a pressure bonding mechanism bonding the bonding surfaces of the substrates to each other by pressurizing

Methodology Applied
Scientific EffectPressure bonding:

Data Source

PatentEP2883644B1Normal temperature bonding device and normal temperature bonding method
Publication Date: 2020.04.29 MITSUBISHI HEAVY IND MACHINE TOOL CO LTD
  • EP2883644B1 patent drawingFigure 1
  • EP2883644B1 patent drawingFigure 2~3
  • EP2883644B1 patent drawingFigure 4~5

AI summary

The purpose of the present invention is to suppress adhering of impurities to substrates and intermediate layers during normal temperature bonding of substrates. This normal temperature bonding device is provided with: a vacuum vessel (1); a first holding mechanism (3a) that holds a first substrate (4); a second holding mechanism (3b) that holds a second substrate (4); a beam source (6) that outputs an activated beam that irradiates surfaces to be bonded of the first substrate (4) and the second substrate (4); and a pressure bonding mechanism (5) that aligns and bonds the surfaces to be bonded of both substrates (4) to which a target material has been made to adhere. At least one of the vacuum vessel (1), the first and second holding mechanisms (3a, 3b), the beam source (6) and the pressure bonding mechanism (5) is formed from or covered with a first material that is not easily sputtered by the activated beam (6) or that does not inhibit the function of devices formed by bonding the two substrates (4) even when present on the surfaces to be bonded.