Semiconductor Groove Formation with Etching Stopper Layer
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Solution Overview
Problem
Semiconductor substrates with different thermal expansion coefficients often warp during bonding, leading to manufacturing yield decreases and electrical characteristic deterioration due to exposure of the adhesive layer during stress relief groove etching.
Innovation Solution
A method of forming stress relief grooves on semiconductor substrates from the opposite surface, using an etching stopper layer to prevent adhesive layer exposure, thereby inhibiting warpage and moisture absorption, and optionally forming through-vias by filling holes with conductive material.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If stress relief grooves are etched to expose the adhesive layer, then warpage is reduced, but electrical characteristics deteriorate due to chemical or water intrusion
Solution Approach 1:
The patent introduces an etching stopper layer as an intermediary between the adhesive layer and the groove. This layer prevents direct exposure of the adhesive layer while still allowing the groove to relieve stress and reduce warpage. The etching stopper layer acts as a mediator that blocks harmful chemicals and water from reaching the adhesive layer, thus preventing electrical characteristic deterioration while maintaining the warpage reduction benefit.
Solution Approach 2:
The etching stopper layer is formed in advance before etching the stress relief groove. This preliminary action ensures that when the groove is etched, the adhesive layer is already protected from exposure. The stopper layer is deposited and patterned before the groove etching step, so that the protective function is in place before any potential harmful intrusion can occur.
2Productivity
If stress relief grooves are etched along grid lines, then manufacturing yield is improved by inhibiting warpage, but adhesive layer exposure causes chemical or water intrusion
Solution Approach 1:
The etching stopper layer serves as a protective intermediary that allows the stress relief groove to function for improving manufacturing yield while simultaneously blocking harmful chemicals and water from intruding into the adhesive layer. The stopper layer is positioned such that it prevents direct communication between the groove and the adhesive layer.
Solution Approach 2:
The patent extracts the harmful function of adhesive layer exposure by removing the direct connection between the groove and the adhesive layer. The etching stopper layer is introduced to take out the vulnerability of adhesive layer exposure, allowing the groove to retain its stress relief function without the harmful side effect of chemical or water intrusion.
3Stress or pressure
If the groove reaches the adhesive layer, then stress relief is achieved, but moisture absorption increases due to adhesive layer exposure
Solution Approach 1:
The etching stopper layer acts as a moisture barrier intermediary that allows the groove to extend deep enough to achieve stress relief while preventing moisture from reaching the adhesive layer. The stopper layer is positioned at a depth that provides sufficient stress relief but blocks moisture absorption pathways.
Solution Approach 2:
The patent applies local quality by making the groove depth non-uniform - the groove extends deep enough to relieve stress in critical areas but is stopped before exposing the adhesive layer. The etching stopper layer enables this localized depth control, allowing different regions to have different groove depths optimized for their specific functions.
Data Source
AI summary
According to one aspect of the present invention, a method of manufacturing a semiconductor device is provided, which includes a bonding step bonding a semiconductor substrate having a semiconductor element disposed on a first surface, to a support substrate, at least through an adhesive layer between the semiconductor substrate and the support substrate, and a groove forming step forming a groove in a scribe area of the semiconductor substrate, from a side of a second surface of the semiconductor substrate, the second surface being opposite to the first surface, and in the groove forming step, a conductive layer between the semiconductor substrate and the support substrate is exposed at a bottom of the groove, without the adhesive layer being exposed in the groove.