Two-Stage Polishing for Semiconductor Bonding Layer Removal
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Solution Overview
Problem
During the manufacturing of stacked-type semiconductor devices using back-side illumination-type CMOS sensors or TSVs, the protrusion of electrically conducting bonding layers at beveled substrate portions can lead to arcing issues, such as substrate breaking, during processes like plasma etching, sputtering, or CVD, due to electrical conductivity.
Innovation Solution
A method involving two-stage polishing with different polishing planes is employed to remove the protruding bonding layer at beveled substrate portions, ensuring the semiconductor elements are protected from damage while preventing arcing by carefully controlling the polishing angles and sequence to completely remove the bonding layer without harming the substrate or functional circuits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the bonding layer is made from an electrically conducting material to ensure good electrical connection, then electrical conductivity is improved, but arcing occurs during plasma processes leading to substrate breaking
Solution Approach 1:
The protruding bonding layer material is selectively removed from the beveled portion of the substrate using CMP polishing. This extraction eliminates the harmful conducting material from locations where it would cause arcing, while preserving the bonding layer's electrical connection function in appropriate areas.
Solution Approach 2:
The bonding layer is treated differently in different locations: it is removed from the beveled portion where it would cause arcing, while being retained in areas where electrical connection is needed. This local differentiation resolves the contradiction by applying the principle of local quality.
2Reliability
If the bonding layer protrudes to the beveled portion to ensure complete substrate bonding, then bonding coverage is improved, but arcing risk increases during plasma processing
Solution Approach 1:
The CMP polishing process is performed in advance of plasma processing to remove protruding bonding layer material from beveled portions. This preliminary action prevents the subsequent arcing problem during plasma processing while maintaining adequate bonding coverage.
3Device complexity
If single-stage polishing is used to remove protruding bonding layer, then process simplicity is maintained, but complete removal without substrate damage is difficult to achieve
Solution Approach 1:
The polishing process is divided into two stages with different polishing planes and parameters. The first stage uses a first polishing plane to perform initial removal, and the second stage uses a second polishing plane to achieve precise final removal. This segmentation enables complete bonding layer removal while preventing substrate damage.
Solution Approach 2:
The polishing process dynamically adjusts parameters between stages: the first polishing plane operates with certain conditions for bulk removal, then transitions to a second polishing plane with different conditions for precision work. This dynamic parameter adjustment resolves the contradiction between complete removal and substrate protection.
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 substrate bonding by preventing arcing and substrate damage, ensuring the semiconductor device manufacturing process can proceed without substrate breakage, thereby improving the overall manufacturing efficiency and product integrity.
Implementation Method 1
polishing a part of the bonding layer formed at a beveled portion of the supporting substrate or the semiconductor substrate with a first polishing plane to remove the part of the bonding layer
Implementation Method 2
polishing a remaining part of the bonding layer formed at the beveled portion of the supporting substrate or the semiconductor substrate with a second polishing plane different from the first polishing plane to remove the remaining part of the bonding layer
Data Source
AI summary
A method for manufacturing a semiconductor device includes bonding a supporting substrate and a first surface of a semiconductor substrate via a bonding layer, processing a second surface of the supporting substrate, opposite to the first surface, to shape the semiconductor substrate into a thin film. After shaping the semiconductor substrate into a thin film, polishing a part of the bonding layer formed at a beveled portion of the supporting substrate or the semiconductor substrate with a first polishing plane to remove the part of the bonding layera A33fter polishing the part of the bonding layer, polishing a remaining part of the bonding layer formed at the beveled portion of the supporting substrate or the semiconductor substrate with a second polishing plane different from the first polishing plane to remove the remaining part of the bonding layer.