SOI Wafer Structure With SiGe Etch Stop for TSV Thickness Control
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Solution Overview
Problem
Existing methods for producing silicon-on-insulator (SOI) wafers face challenges in achieving high yield with defect-free device layers and minimal thickness variation while maintaining cost-effectiveness.
Innovation Solution
A semiconductor structure is fabricated with a reverse SOI configuration, utilizing a through-silicon via (TSV) that couples circuitry on the front and backside of a device layer, involving an epitaxial tri-layer formation, selective etching, and wafer bonding, which includes a SiGe etch stop layer for precise thickness control and defect reduction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional methods are used to produce SOI wafers, then production cost is reduced, but yield and defect-free device layers deteriorate
Solution Approach 1:
The substrate is divided into multiple regions with different device layer thicknesses, allowing different portions to be optimized for different functions. Thinner regions provide better electrical isolation while thicker regions maintain mechanical strength, enabling high-yield production without sacrificing device performance
Solution Approach 2:
The device layer thickness is varied across different regions of the substrate rather than maintaining uniform thickness. This parameter change allows optimization of both yield and device performance by having thinner regions for better isolation and thicker regions for mechanical stability
2Reliability
If methods producing defect-free device layers are used, then reliability is improved, but thickness variation worsens
Solution Approach 1:
Different regions of the substrate have different device layer thicknesses tailored to local requirements. This local quality approach ensures that each region has the optimal thickness for its specific function, maintaining both defect-free layers and appropriate thickness variation for performance optimization
3Manufacturing precision
If uniform thickness SOI wafers are produced, then manufacturing precision is improved, but yield deteriorates
Solution Approach 1:
The substrate is segmented into regions with different thickness characteristics, allowing the overall wafer to achieve high yield while individual regions maintain appropriate thickness uniformity for their specific functions
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
The method achieves high-yield, defect-free SOI wafers with minimal thickness variation and cost-effective production by leveraging the SiGe etch stop layer for precise thickness control and efficient etching processes.
Implementation Method 1
an epitaxial tri-layer formation, selective etching, and wafer bonding, which includes a SiGe etch stop layer for precise thickness control
Implementation Method 2
an epitaxial tri-layer formation
Implementation Method 3
wafer bonding, which includes a SiGe etch stop layer for precise thickness control
Data Source
AI summary
The present disclosure provides a semiconductor structure, including: a semiconductor device layer including a first surface and a second surface, wherein the first surface is at a front side of the semiconductor device layer, and the second surface is at a backside of the semiconductor device layer; an insulating layer above the second surface of the semiconductor device; and a through-silicon via (TSV) traversing the insulating layer. Associated manufacturing methods of the same are also provided.