Buried Cavity Semiconductor Substrate with Oxide Support
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing semiconductor substrate manufacturing techniques, such as SIMOX and SmartCut, involve ion implantation and wafer bonding, which are costly and complex, while Silicon on Nothing (SON) technology compromises mechanical stability by using unfilled voids as buried insulators.
Innovation Solution
A semiconductor substrate with buried cavities and dielectric support structures, where bottleneck-shaped trenches are formed and oxidized to create vertical oxide columns that support the substrate, maintaining mechanical stability without relying on lateral edges for support.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If unfilled voids are used as buried insulators in SON technology, then dielectric properties are improved, but mechanical stability deteriorates
Solution Approach 1:
The patent combines unfilled voids (air) with dielectric support structures (oxide columns) to create a composite buried insulator system. The air provides excellent dielectric properties while the oxide support structures provide mechanical strength, resolving the contradiction between dielectric performance and mechanical stability.
Solution Approach 2:
The patent applies different materials in different locations: unfilled voids are used in regions where dielectric properties are prioritized, while dielectric support structures are strategically placed in regions where mechanical support is needed. This local differentiation allows optimization of both dielectric properties and mechanical stability in their respective zones.
2Reliability
If ion implantation and wafer bonding are used to form SOI substrates, then buried insulator quality is improved, but manufacturing complexity increases
Solution Approach 1:
The patent extracts and eliminates the complex ion implantation and wafer bonding steps from the manufacturing process. Instead, it uses a simplified approach with bottleneck-shaped trenches that are oxidized to form the buried insulator, removing the disturbing complex steps while maintaining buried insulator quality.
Solution Approach 2:
The patent changes the manufacturing approach from physical/chemical processes (ion implantation, wafer bonding) to a thermal oxidation process. This parameter change in the manufacturing method simplifies the process while still achieving high-quality buried insulators through controlled oxidation of the bottleneck-shaped trenches.
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 the production of substrates with improved mechanical stability and favorable dielectric properties, enabling the formation of continuous active device regions without the expense and complexity of ion implantation and wafer bonding, and offering better electrical isolation than traditional SOI substrates.
Implementation Method 1
bottleneck-shaped trenches are formed and oxidized to create vertical oxide columns that support the substrate
Data Source
AI summary
A semiconductor device includes a semiconductor substrate with a first surface. The device further includes one or more semiconductor devices formed or the first surface in an active area. The device further includes a plurality of cavities in the semiconductor substrate beneath the first surface. The device further includes dielectric support structures between each of the cavities and spaced apart from the first surface. The dielectric support structures support a part of the semiconductor substrate between the active area and the cavities. The dielectric support structures include an oxide.