Wafer Bonding Plasma Grid Layout for Crystal-Direction Uniformity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Semiconductor manufacturers face challenges in achieving uniform bond strength and minimizing distortion caused by anisotropy in wafer bonding processes, particularly when bonding wafers with different crystallographic orientations.
Innovation Solution
A plasma grid assembly design in a remote plasma system is used to modulate plasma intensity along different in-plain crystal directions of a wafer during the plasma activation process, which helps in reducing bonding wave propagation speed and bond strength differences between various crystal directions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional plasma activation process is used without modulation, then the bonding process is simple, but bond strength uniformity deteriorates due to anisotropy in different crystal directions
Solution Approach 1:
The plasma grid assembly is segmented into multiple regions (first plurality of regions and second plurality of regions) with different plasma generation characteristics. Each region is independently configured to provide tailored plasma activation to specific areas of the wafer, thereby compensating for anisotropy in different crystal directions and achieving uniform bond strength across the entire wafer surface.
Solution Approach 2:
Different regions of the plasma grid assembly are designed with different plasma generation capabilities to provide localized plasma activation. The first plurality of regions generates plasma with different intensity or distribution characteristics compared to the second plurality of regions, allowing each region to address the specific anisotropy requirements of its corresponding wafer area.
2Stability of the object's composition
If uniform plasma activation is applied across the wafer, then the plasma activation process is simple, but distortion caused by anisotropy increases
Solution Approach 1:
The plasma grid assembly divides the wafer surface into multiple regions that receive differentiated plasma activation. This segmentation allows each region to be activated according to its specific crystallographic orientation requirements, preventing the uniform activation-induced distortion that would occur with conventional single-zone plasma sources.
Solution Approach 2:
The plasma grid assembly modifies plasma parameters (intensity, distribution, or activation level) across different regions to compensate for anisotropy. By changing plasma parameters locally rather than uniformly, the system reduces wafer distortion while maintaining effective bonding activation.
3Manufacturing precision
If plasma activation is not modulated by crystal direction, then the plasma system is simpler, but bond strength differences between crystal directions increase
Solution Approach 1:
The plasma grid assembly is divided into regions that correspond to different crystal directions on the wafer. Each segmented region is configured to provide plasma activation tailored to its specific crystal orientation, thereby eliminating bond strength variations between different crystal directions through spatially-resolved plasma control.
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 reduces distortion caused by anisotropy, minimizes bubble defects, and improves bond strength uniformity, leading to more reliable and consistent wafer bonding results.
Implementation Method 1
performing a first plasma activation process on a first surface of a first wafer... exposing the first surface of the first wafer to a first plasma through the plasma grid assembly
Implementation Method 2
The first plasma activation process forms a first plurality of silicon dangling bonds on the first surface of the first wafer... The first cleaning process forms a first plurality of silanol groups on the first surface of the first wafer
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.