SOI Wafer Gettering Layer Oxygen Precipitation
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Solution Overview
Problem
Conventional SOI wafers have a low gettering ability, which restricts the diffusion of metal impurities from the monocrystalline silicon layer to the gettering site, especially when the BOX layer is thick, leading to reduced reliability and increased process complexity in semiconductor device manufacturing.
Innovation Solution
An SOI wafer structure with a gettering layer composed of silicon containing oxygen, carbon, and nitrogen, positioned immediately under the BOX layer, enhances the gettering ability by forming a gettering site through oxygen precipitation, allowing efficient capture of metal impurities without the need for additional impurity diffusion layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional gettering methods are used in SOI wafers, then the manufacturing process becomes complex with additional impurity diffusion layers, but the gettering efficiency remains insufficient
Solution Approach 1:
The patent segments the wafer structure into functionally distinct layers, with the gettering layer being a separate, dedicated component. This segmentation allows the gettering function to be achieved through a single, well-defined layer rather than through complex multi-step impurity diffusion processes, thereby improving gettering efficiency while maintaining manufacturing simplicity.
Solution Approach 2:
The patent applies local quality by creating a gettering layer with specific properties (oxygen-rich silicon) localized at the interface between the monocrystalline silicon layer and the BOX layer. This localized gettering structure provides efficient impurity capture exactly where needed, without requiring complex process steps throughout the entire wafer.
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 structure significantly improves the gettering efficiency, reducing crystal defects and junction leakage, while maintaining the quality of the monocrystalline silicon layer and simplifying the manufacturing process by eliminating the need for proximity gettering steps, thus enhancing the reliability and performance of semiconductor devices.
Implementation Method 1
a method in which an oxygen precipitation or crystal defect is used to form a crystal deformation in a deep region (several tens μm deep from the surface) where no device in the wafer is formed so that the crystal deformation can capture metal atoms
Data Source
AI summary
An SOI wafer including: a supporting substrate 1; a BOX layer 2 provided above the supporting substrate 1, the BOX layer 2 being formed by a thermal oxidization; a gettering layer 3 provided immediately on the BOX layer 2 and mainly composed of a silicon which contains one or more of oxygen, carbon and nitrogen and contains at least oxygen; and an S layer 4 in which semiconductor devices are to be formed, the S layer 4 being mainly composed of a monocrystalline silicon.