Low Density Silicon Oxide Fusion Bonding Debonding
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Solution Overview
Problem
Conventional fusion bonding techniques provide strong bonding but make debonding difficult, especially in advanced substrate processing flows where easy separation of substrates is required.
Innovation Solution
The method involves fusion bonding substrates with a low density silicon oxide surface, followed by using a wet etch, such as dilute hydrofluoric acid, to debond the substrates by etching away the bonded layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If fusion bonding is used to bond substrates, then bonding strength is improved, but debonding difficulty increases
Solution Approach 1:
The bonding interface is segmented into two distinct layers: a strong-bonding silicon oxide layer for initial substrate bonding, and a weak-bonding low-density silicon oxide layer for easy debonding. This segmentation allows the system to achieve both strong bonding and easy separation by targeting different layers for different functions.
Solution Approach 2:
Different regions of the bonding interface have different properties: the silicon oxide layer provides strong chemical bonding for initial attachment, while the low-density silicon oxide layer provides weak bonding that allows easy debonding. This local differentiation of bonding strength at the interface enables both strong bonding and easy separation.
2Ease of operation
If adhesive bonding with thick films is used, then ease of debonding is improved, but manufacturing precision deteriorates
Solution Approach 1:
The density parameter of the silicon oxide layer is changed to create a low-density variant that is easily etched by hydrofluoric acid. This parameter change enables easy debonding through chemical etching while maintaining thin film thickness for good lithography patterning precision.
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 allows for effective bonding while enabling easy debonding of substrates, overcoming the challenges of strong bonding in fusion bonding processes.
Implementation Method 1
Fusion bonding of the substrates may then be performed. In fusion bonding, chemical bonds are formed between the two surfaces of the two substrates.
Implementation Method 2
a wet etch may then be utilized to debond the substrates by etching away the layers that have been bonded. In one exemplary etch, a dilute hydrofluoric acid (DFH) etch is utilized to etch the bonded silicon oxide surface
Data Source
AI summary
Described herein is a method of bonding and/or debonding substrates. In one embodiment, at least one of the surfaces of the substrates to be bonded is comprised of an oxide. In one embodiment, the surfaces of both substrates comprise an oxide. A wet etch may then be utilized to debond the substrates by etching away the layers that have been bonded. In one embodiment, a fusion bonding process is utilized to bond two substrates, at least one substrate having a silicon oxide surface. In one exemplary etch, a dilute hydrofluoric (DHF) etch is utilized to etch the bonded silicon oxide surface, allowing for two bonded substrates to be debonded. In another embodiment, the silicon oxide may be a low density silicon oxide. In one embodiment, both substrates may have a surface layer of the low density silicon oxide which may be fusion bonded together.