Semiconductor Wafer Backside Oxide Control for Stable Grinding
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Solution Overview
Problem
The challenge in manufacturing semiconductor devices with large diameter wafers is the inability to effectively grind the back surface due to the formation of a mirror surface during oxidation, leading to potential overcurrent issues and reduced reliability.
Innovation Solution
A method involving the formation of a silicon oxide film on both main surfaces of the semiconductor substrate, followed by a redistribution wiring process using a plating method, and controlled grinding of the silicon oxide film on the back surface to a thickness between 10 nm and 30 nm to prevent foreign substance generation and ensure smooth grinding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the back surface is ground on a mirror surface, then grinding can be performed, but the grind blade rotation stops soon and grinding cannot be normally performed due to overcurrent
Solution Approach 1:
A silicon oxide film is formed on the back surface before grinding to modify the surface properties. This preliminary action prevents the mirror surface from causing grind blade stoppage during grinding, allowing the grinding process to proceed normally without overcurrent issues.
Solution Approach 2:
The surface characteristics of the back surface are changed by forming a silicon oxide film with specific thickness (10 nm to 30 nm). This parameter change modifies the friction and heat generation characteristics during grinding, preventing the mirror surface effect that causes grind blade stoppage.
2Object-affected harmful factors
If the silicon oxide film thickness is too thin, then foreign substances may be generated during plating, but if too thick, grinding becomes difficult
Solution Approach 1:
The silicon oxide film thickness is precisely controlled within the range of 10 nm to 30 nm. This specific parameter range is optimized to provide sufficient coverage to prevent foreign substance generation during plating while remaining thin enough to allow effective grinding without excessive difficulty.
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 enhances the reliability of the manufacturing process by preventing foreign substance formation and enabling effective thinning of the semiconductor substrate without the need for additional protection tapes, thus maintaining grinding efficiency and reducing manufacturing costs.
Implementation Method 1
forming a silicon oxide film covering each of the first main surface and the second main surface
Implementation Method 2
grinding the silicon oxide film positioned on the second main surface and the second main surface
Data Source
AI summary
A method of manufacturing a semiconductor device includes: forming a silicon oxide film covering each of a first main surface and a second main surface of a semiconductor substrate; forming a redistribution wiring on the first main surface side of the semiconductor substrate; and grinding the second main surface of the semiconductor substrate. This grinding step is performed in a state in which a thickness of the silicon oxide film positioned on the second main surface is equal to or larger than 10 nm and equal to or smaller than 30 nm.