Semiconductor Substrate Bonding With an Intermediate Expansion Layer
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The bonding of substrates with different linear expansion coefficients, such as compound semiconductor and silicon substrates, often results in misalignment, warpage, and deformation during heat-bonding, leading to reliability issues in semiconductor apparatuses.
Innovation Solution
A manufacturing method that involves an intermediate member with a third substrate having a linear expansion coefficient closer to that of the first substrate, which is interposed between the first and second substrates, allowing for bonding at normal temperatures and reducing misalignment and warpage by minimizing the difference in expansion coefficients.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If substrates with different linear expansion coefficients are bonded together by heating, then bonding reliability is improved, but misalignment and warpage occur during the bonding process
Solution Approach 1:
The patent introduces a third substrate with a linear expansion coefficient that is intermediate between the first substrate (compound semiconductor) and the second substrate (silicon). This intermediate substrate acts as a mediator during heat-bonding, reducing the thermal expansion mismatch and preventing misalignment and warpage while still enabling reliable bonding through heating.
Solution Approach 2:
The patent changes the physical parameter (linear expansion coefficient) of the bonding system by introducing a third substrate with an intermediate expansion coefficient. This parameter adjustment allows the system to withstand thermal bonding conditions without suffering from the harmful effects of large expansion coefficient differences.
2Strength
If substrates with different linear expansion coefficients are bonded together by heating, then bonding strength is improved, but substrate deformation occurs
Solution Approach 1:
The third substrate serves as a mediator that buffers the thermal expansion stress between the first and second substrates. By having an intermediate linear expansion coefficient, it reduces the differential expansion forces that cause warpage and deformation, thereby maintaining substrate shape stability during heat-bonding while still achieving strong bonding.
Solution Approach 2:
The patent explicitly utilizes the principle of thermal expansion by selecting a third substrate whose linear expansion coefficient is intermediate between the other two substrates. This strategic selection allows the system to accommodate thermal expansion differences during heating, preventing excessive stress and deformation while maintaining bonding strength.
3Device complexity
If direct bonding between compound semiconductor and silicon substrates is performed, then process complexity is reduced, but misalignment occurs due to expansion coefficient difference
Solution Approach 1:
The patent introduces a third substrate as an intermediate layer between the compound semiconductor substrate and the silicon substrate. While this adds one more layer to the structure, it significantly improves alignment precision during superimposition by reducing thermal expansion mismatch, thereby resolving the trade-off between structural simplicity and manufacturing precision.
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 method effectively reduces misalignment and warpage, enhancing the reliability of the bonding process and enabling the production of semiconductor apparatuses with narrower pixel pitches and higher reliability.
Implementation Method 1
the third substrate has such a linear expansion coefficient that a difference between the linear expansion coefficient of the third substrate and the linear expansion coefficient of the first substrate is smaller than a difference between the linear expansion coefficients of the first substrate and the second substrate
Data Source
AI summary
A manufacturing method of a semiconductor apparatus includes preparing an intermediate member that includes a first member having a first substrate comprising a semiconductor element formed thereon, a second member having a second substrate, the second substrate including a part of a circuit electrically connected to the semiconductor element and having a linear expansion coefficient different from that of the first substrate, and a third member having a third substrate showing such a linear expansion coefficient that a difference between itself and the linear expansion coefficient of the first substrate is smaller than a difference between the linear expansion coefficients of the first substrate and the second substrate, and includes bonding the first member and the second member together. A first bonding electrode containing copper electrically connected to the semiconductor element and a second bonding electrode containing copper electrically connected to the circuit are bonded together.