Semiconductor Substrate Stacking via Direct Bonding and Thinning
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Solution Overview
Problem
Current semiconductor device manufacturing methods face challenges in increasing mounting density due to limitations in substrate bonding and thinning processes, which affect the efficiency and quality of stacked semiconductor devices.
Innovation Solution
A semiconductor device manufacturing method that involves repeated bonding and thinning of substrates using direct bonding techniques without adhesive layers, allowing for the formation of a stacked substrate that can be cut into multiple stacked bodies, thereby increasing chip density and improving device packaging efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If adhesive layers are used for substrate bonding, then bonding strength is improved, but mounting density deteriorates due to increased substrate thickness
Solution Approach 1:
The invention extracts and eliminates the adhesive layer from the substrate bonding process. By performing direct bonding between substrates without any adhesive intermediary, the patent removes the source of excessive thickness while maintaining bonding strength through direct substrate-to-substrate contact.
Solution Approach 2:
The invention uses an intermediary substance (bonding agent or plasma treatment) to enable direct bonding between substrates. This intermediary facilitates chemical bonding at the substrate interface without adding significant thickness, allowing strong adhesion while maintaining thin overall substrate structure.
2Quantity of substance
If multiple substrates are stacked to increase mounting density, then chip density is improved, but manufacturing complexity deteriorates
Solution Approach 1:
The invention segments the manufacturing process into standardized repetitive units: bond-substrate, thin-substrate, bond-substrate, thin-substrate. This segmentation allows the complex multi-substrate stacking to be broken down into simple, repeatable cycles that can be automated and controlled systematically.
Solution Approach 2:
The invention performs preliminary thinning of substrates before bonding, and preliminary preparation of bonding surfaces. By preparing substrates in advance with appropriate thickness and surface treatment, the actual bonding process becomes simpler and more reliable, reducing overall manufacturing complexity.
3Volume of moving object
If substrates are thinned to increase stacking height, then mounting density is improved, but substrate strength deteriorates
Solution Approach 1:
The invention creates a composite structure by bonding multiple thinned substrates together. Individual substrates can be very thin and weak, but when stacked and bonded in sequence, the composite structure achieves the required overall strength while maintaining low individual substrate thickness for high mounting density.
Solution Approach 2:
The invention applies surface treatments or coating layers to thinned substrates before bonding to cushion and protect the weak substrate structure. These protective layers prevent damage during handling and bonding while allowing the substrate to remain thin for high density stacking.
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 method enhances the mounting density of semiconductor devices by allowing for more substrates to be stacked at a predetermined height and efficiently separating them into individual packages, improving the reliability and memory capacity of the devices.
Implementation Method 1
a first main surface of a first substrate and a second main surface of a second substrate are bonded to each other
Data Source
AI summary
In a semiconductor device manufacturing method, a stacked substrate is formed. In the stacked substrate, a substrate is stacked repeatedly multiple times. The substrate includes a plurality of chip regions. In the semiconductor device manufacturing method, the stacked substrate is cut in a stacking direction among the plurality of chip regions, to separate the stacked substrate into a plurality of stacked bodies. In forming the stacked substrate, a first main surface of a first substrate and a second main surface of a second substrate are bonded to each other. In forming the stacked substrate, in a state where the second main surface is bonded to the first main surface, a third main surface of the second substrate opposite to the second main surface is thinned. In forming the stacked substrate, the third main surface of the second substrate and a fourth main surface of a third substrate are bonded to each other. In forming the stacked substrate, in a state where the fourth main surface is bonded to the third main surface, a fifth main surface of the third substrate opposite to the fourth main surface is thinned.