Solid-State Imaging Device Warpage Control via Adhesion Layer
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Solution Overview
Problem
The challenge is to suppress warpage generated by bonding substrates with different thermal expansion coefficients while meeting the requirements of miniaturization in solid-state imaging devices, as existing technologies struggle to achieve both miniaturization and warpage reduction simultaneously.
Innovation Solution
A solid-state imaging device is designed with a semiconductor substrate, a glass substrate, an adhesion layer, and a warpage correction film, where the warpage correction film is strategically placed between the adhesion layer and one of the substrates to optimize thermal expansion coefficients and stress, allowing for the thinning of substrates and reduction of warpage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If substrates with different thermal expansion coefficients are heat-bonded together, then bonding strength is improved, but warpage is generated when temperature returns to room temperature
Solution Approach 1:
An adhesion layer is introduced as an intermediary between the semiconductor substrate and glass substrate. This adhesion layer has thermal expansion coefficients and stress characteristics optimized to be between those of the two substrates, acting as a buffer that reduces the thermal expansion mismatch and prevents warpage while maintaining bonding strength
Solution Approach 2:
The patent optimizes the thermal expansion coefficients and stress parameters of the adhesion layer to fall between those of the semiconductor substrate and glass substrate. By carefully selecting and controlling these material parameters, the adhesion layer compensates for the thermal expansion difference between the two bonded substrates, preventing warpage formation
2Length of moving object
If substrate thickness is reduced to meet miniaturization requirements, then device size is improved, but warpage suppression becomes more difficult
Solution Approach 1:
The adhesion layer's thermal expansion coefficient and stress are precisely controlled to fall between those of the semiconductor substrate and glass substrate. This parameter optimization allows the adhesion layer to compensate for thermal expansion differences even when substrates are thin, enabling miniaturization without excessive warpage
Solution Approach 2:
The patent employs a composite structure consisting of the semiconductor substrate, adhesion layer, and glass substrate. The adhesion layer acts as a composite material with intermediate properties that bridge the two substrates, providing both mechanical bonding and thermal expansion compensation in a thin-film configuration suitable for miniaturization
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 configuration enables the miniaturization of solid-state imaging devices by reducing warpage and distortion, allowing for thinner substrates and improved thermal expansion coefficient management, enhancing the reliability and cost-effectiveness of the semiconductor process.
Implementation Method 1
substrates with thermal expansion coefficients of which are different from each other are heat-bonded to an adhesion layer
Implementation Method 2
substrates with thermal expansion coefficients of which are different from each other are heat-bonded to an adhesion layer
Data Source
AI summary
There is provided solid-state imaging devices and methods of forming the same, the solid-state imaging devices including: a semiconductor substrate; a glass substrate; an adhesion layer provided between the semiconductor substrate and the glass substrate; and a warpage correction film provided adjacent to one of the semiconductor substrate and the glass substrate.