Plasma Grid Modulation in Wafer Bonding for Uniform 3DIC Bonding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Semiconductor manufacturers face challenges in achieving uniform bond strength and minimizing distortion in three-dimensional integrated circuits (3DICs) due to anisotropy in mechanical properties of wafers, leading to issues like bubble defects and non-uniform bond strength across different crystallographic directions.
Innovation Solution
A plasma grid assembly design in a remote plasma system is used to modulate plasma intensity during the plasma activation process, allowing for uniform plasma activation along different in-plane crystal directions of the wafer, which reduces bond wave propagation speed and strength differences, thereby minimizing distortion and improving bond strength uniformity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional plasma activation is used without modulation, then the activation process is simple, but bond strength uniformity deteriorates due to anisotropy in mechanical properties of wafers
Solution Approach 1:
The plasma grid assembly is divided into multiple regions (first plurality of regions and second plurality of regions) that correspond to different crystallographic directions of the wafer. Each region applies different plasma intensity to compensate for the anisotropic mechanical properties of the wafer, thereby achieving uniform bond strength across all directions while addressing the technical contradiction between manufacturing precision and device complexity.
2Manufacturing precision
If uniform plasma activation is applied to all crystal directions, then bond strength uniformity improves, but distortion increases due to anisotropy in mechanical properties
Solution Approach 1:
Different plasma intensities are applied to different regions of the wafer based on their crystallographic directions. The plasma grid assembly creates non-uniform plasma distribution that specifically addresses the anisotropic mechanical properties, reducing distortion while achieving bond strength uniformity and resolving the contradiction between manufacturing precision and shape stability.
3Shape
If plasma intensity is modulated according to crystal directions, then distortion is reduced, but the plasma activation process becomes more complex
Solution Approach 1:
The plasma grid assembly is segmented into multiple discrete regions that can be independently controlled. This segmentation allows the system to address complex anisotropic distortion patterns by applying tailored plasma intensity to each region, reducing overall distortion while managing the complexity through modular regional control rather than continuous complex patterns.
Solution Approach 2:
The plasma grid assembly implements local quality by assigning different plasma intensities to specific regions corresponding to different crystallographic directions. This localized control approach reduces wafer distortion by addressing anisotropic properties directionally, while the modular regional structure manages the overall system complexity in a practical manner.
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
The solution effectively reduces distortion and enhances bond strength uniformity across different crystallographic directions, improving the yield and performance of 3DICs by ensuring consistent bonding across various in-plane directions.
Implementation Method 1
A plasma grid assembly design in a remote plasma system is used to modulate plasma intensity during the plasma activation process
Implementation Method 2
reduces bond wave propagation speed and strength differences, thereby minimizing distortion and improving bond strength uniformity
Data Source
AI summary
Wafer bonding apparatus and method are provided. A method includes performing a first plasma activation process on a first surface of a first wafer. The first plasma activation process forms a first high-activation region and a first low-activation region on the first surface of the first wafer. A first cleaning process is performed on the first surface of the first wafer. The first cleaning process forms a first plurality of silanol groups in the first high-activation region and the first low-activation region. The first high-activation region includes more silanol groups than the first low-activation region. The first wafer is bonded to a second wafer.