Semiconductor Layer Bonding for Etching Resistance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for fabricating electronic device stacks, such as transistors, using direct oxide/oxide bonding result in poor quality bonding interfaces, leading to infiltration and lift-off during etching processes, and require high thermal budgets that are incompatible with many electronic devices.
Innovation Solution
The method involves direct bonding between semiconductor layers, introducing dopants to form a ground plane, and performing a crystallization step to improve bonding interface quality, allowing for hydrophobic bonding and reducing the need for high thermal annealing, with optional steps like surface treatment and planarization to enhance bonding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If direct oxide/oxide bonding is used to bond structures, then the bonding process is simple and fast, but the bonding interface quality is poor leading to infiltration and lift-off during etching
Solution Approach 1:
The patent changes the material parameter of the bonding interface from oxide/oxide to semiconductor/semiconductor. This fundamental material parameter change enables hydrophobic bonding with superior closing quality that resists etching agent infiltration, while maintaining process efficiency
Solution Approach 2:
The patent employs a composite structure where semiconductor layers are bonded to form the interface, combining the advantages of hydrophobic bonding (etching resistance) with semiconductor material properties. This composite approach at the interface level solves both reliability and productivity requirements
2Reliability
If reinforcement thermal annealing with high thermal budget is applied to improve bonding interface closing quality, then the bonding interface becomes more resistant to etching, but the electronic devices are impaired due to excessive thermal stress
Solution Approach 1:
The patent performs preliminary surface treatment of semiconductor layers (such as hydrophobization) before bonding to ensure optimal bonding conditions. This preliminary action creates a bonding interface that inherently resists etching without requiring subsequent high-temperature annealing that would damage devices
Solution Approach 2:
The patent changes the bonding material from oxide to semiconductor, which fundamentally alters the bonding mechanism to hydrophobic bonding. This parameter change eliminates the need for high-temperature thermal annealing while achieving superior interface closing quality that resists etching infiltration
3Ease of manufacture
If oxide layers are used for bonding, then the bonding process is straightforward, but the bonding interface is partially open and allows extensive infiltration of etching agents
Solution Approach 1:
The patent changes the material composition parameter from oxide to semiconductor at the bonding interface. This change transforms the bonding characteristics to hydrophobic bonding, which naturally provides complete interface closing and prevents etching agent infiltration, while maintaining manufacturing simplicity through direct bonding
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 results in a robust bonding interface resistant to wet chemistry etching and eliminates the need for high thermal budgets, ensuring better device integrity and reducing defectivity by maintaining a high-quality bonding interface without extensive thermal stress.
Implementation Method 1
bonding the first and second structures by direct bonding between the first and second semiconductor layers so as to form a bonding interface... due to the hydrophobic bonding of step c)
Implementation Method 2
introducing dopants into the first and second semiconductor layers so as to form a ground plane
Implementation Method 3
the method comprises a crystallization step of the amorphous film or films so that a crystallization front is propagated at the bonding interface
Implementation Method 4
obtain a bonding interface with a good closing quality (resistant in particular to wet chemistry etching processes) due to the hydrophobic bonding
Data Source
AI summary
This method includes the following steps: a) providing a first structure successively including a substrate, an electronic device, a dielectric layer, and a first semiconductor layer; b) providing a second structure successively including a substrate, an active layer, a dielectric layer, and a second semiconductor layer, the active layer being designed to form an electronic device; c) bonding the first and second structures by direct bonding between the first and second semiconductor layers so as to form a bonding interface; d) removing the substrate of the second structure so as to expose the active layer; e) introducing dopants into the first and second semiconductor layers so as to form a ground plane.