Wafer Bonding via Selective Oxide Deposition
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Solution Overview
Problem
Current wafer bonding techniques often result in corner rounding, voids, and roughness of interconnect structures due to etching processes, which can hinder proper alignment and expansion during bonding, affecting the efficiency and reliability of semiconductor packages.
Innovation Solution
The method involves selective deposition of oxide materials over dielectric layers on wafers, followed by alignment and bonding using a hybrid technique, which minimizes the need for recessing and enhances the bonding process by forming a channel between interconnect structures, thereby avoiding corner rounding and roughness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If etching techniques are used to recess interconnect structures for alignment, then proper alignment and expansion during bonding can be achieved, but corner rounding, voids, and roughness of interconnect structures occur
Solution Approach 1:
The patent removes the harmful etching process entirely and replaces it with a deposition-based approach. Instead of recessing interconnect structures through etching, the invention deposits oxide materials selectively on dielectric layers to create bonding surfaces, thereby extracting the source of corner rounding, voids, and roughness while maintaining alignment capability
Solution Approach 2:
The patent changes the fundamental parameter of the bonding preparation process from material removal (etching) to material addition (deposition). By depositing oxide materials with controlled thickness and selectivity, the process achieves alignment without the detrimental shape changes caused by etching, thus changing the process parameter from negative to positive material interaction
2Shape
If selective deposition of oxide materials is performed over dielectric layers, then corner rounding and roughness are avoided, but additional deposition process time is required
Solution Approach 1:
The patent performs preliminary deposition of oxide materials on dielectric layers before the bonding step. This preliminary action prepares the bonding surfaces in advance, ensuring that when bonding occurs, the interconnect structures maintain their integrity without requiring subsequent corrective processes, thus eliminating time waste from rework
Solution Approach 2:
The patent merges the alignment and bonding preparation steps into a single deposition process. By depositing oxide materials that simultaneously provide both alignment references and bonding surfaces, the process combines multiple functions into one operation, reducing the total number of process steps and overall bonding time
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 improves the efficiency of wafer bonding by reducing time and ensuring precise alignment, while maintaining the integrity of interconnect structures, leading to enhanced Power-Performance-Area-Cost (PPAC) scaling for complex circuits.
Implementation Method 1
A selective deposition technique can be performed to deposit oxide materials over the top surface of the dielectric layers
Implementation Method 2
the first and second substrates can be heated/annealed, thereby expanding and physically connecting the interconnect structures of the two wafers
Implementation Method 3
the two wafers (e.g., with one of the wafers flipped) can be aligned and bonded/connected/coupled via the oxide materials
Data Source
AI summary
A semiconductor package is disclosed. The semiconductor package includes a first substrate including a first interconnect structure and a first bonding layer adjacent the first interconnect structure. The semiconductor package includes a second substrate including a second interconnect structure and a second bonding layer adjacent the second interconnect structure. The first bonding layer and second bonding layer each include a metal oxide.