Au-Sb Alloy Back Electrode Uniformity on Large Wafers
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Solution Overview
Problem
As semiconductor wafer sizes increase, forming a uniform gold-antimony alloy layer by vapor deposition becomes difficult, leading to inadequate ohmic contact and peeling issues when using the sputtering method, resulting in suboptimal semiconductor device characteristics.
Innovation Solution
A semiconductor device with a gold-antimony alloy layer formed by the sputtering method using a target with an antimony concentration of 22 wt% to 37 wt%, and a thickness of 20 nm to 45 nm, ensuring adequate antimony diffusion for reduced resistivity and improved adhesion between the alloy layer and the semiconductor substrate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the vapor deposition method is used to form a gold-antimony alloy layer on large semiconductor wafers, then uniformity of the alloy layer becomes difficult to achieve, but the method was traditionally used for forming such layers
Solution Approach 1:
The patent changes the deposition method from vapor deposition to sputtering, and optimizes parameters including antimony concentration (15-37 wt%) and layer thickness (20-45 nm) to achieve uniform alloy layer formation on large semiconductor wafers
2Area of stationary object
If the sputtering method is used to form a gold-antimony alloy layer, then the layer can be formed on large wafers, but adequate ohmic contact cannot be formed and the back electrode may peel off
Solution Approach 1:
The patent optimizes critical parameters including antimony concentration (15-37 wt%) and layer thickness (20-45 nm) to achieve both adequate ohmic contact and strong adhesion when using the sputtering method, resolving the reliability issues
Solution Approach 2:
The patent uses a composite gold-antimony alloy material with specific composition ratios, combining the advantages of both gold (conductivity) and antimony (adhesion and ohmic contact) to achieve reliable electrical and mechanical performance
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 approach enhances semiconductor device characteristics by achieving both low resistivity and strong adhesion between the semiconductor substrate and the back electrode, optimizing device performance.
Implementation Method 1
forming an electrode including a gold-antimony (Au—Sb) alloy layer on the semiconductor wafer by a sputtering method
Implementation Method 2
ensuring adequate antimony diffusion for reduced resistivity and improved adhesion between the alloy layer and the semiconductor substrate
Data Source
AI summary
A characteristic of a semiconductor device having a back electrode including an Au—Sb alloy is improved. The semiconductor device has a semiconductor substrate and the back electrode including the Au—Sb alloy layer. The back electrode is formed on the semiconductor substrate. The Sb concentration in the Au—Sb alloy layer is equal to or greater than 15 wt %, and equal to or less than 37 wt %. The thickness of the Au—Sb alloy layer is equal to or larger than 20 nm, and equal to or less than 45 nm.