Immersion Interconnections for Semiconductor Stacking
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Solution Overview
Problem
Current semiconductor packaging techniques face challenges in achieving high-density, low-power, and low-latency performance due to limitations in miniaturization and interconnection methods, particularly in stacked semiconductor devices where precise alignment and low-stress bonding are required.
Innovation Solution
The use of spacers to align and bond semiconductor devices, followed by an electroless plating process to form immersion interconnections between contact pads, allowing for low-temperature, stress-free connections that enhance coplanarity and alignment, and enable cost-effective, high-density chip stacking.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional bonding techniques (direct bonding, thermo-compressive bonding, etc.) are used to bond semiconductor wafers, then electrical connections can be established between stacked wafers, but high mechanical stress and thermal stress are introduced during the bonding process
Solution Approach 1:
The patent replaces mechanical bonding systems (thermo-compressive bonding, direct bonding) with a chemical deposition system. The immersion interconnection structure is formed through electroless plating of conductive material into recesses, eliminating the need for high-stress mechanical bonding processes while establishing reliable electrical connections between stacked semiconductor devices
Solution Approach 2:
The patent changes the bonding parameters from high-temperature and high-pressure conditions to low-temperature electroless plating conditions. The immersion interconnection structure is formed at temperatures below 100°C through chemical deposition, significantly reducing thermal and mechanical stress compared to conventional bonding techniques
2Manufacturing precision
If minimum feature size is reduced to increase integration density, then more components can be integrated into a given area, but alignment precision becomes more difficult to achieve in stacked devices
Solution Approach 1:
The patent performs preliminary alignment by forming recesses in the first semiconductor device before stacking. The immersion interconnection structure is then formed by filling these pre-defined recesses with conductive material, ensuring precise alignment without requiring post-stacking adjustment. This preliminary structuring enables high integration density while maintaining alignment precision
Solution Approach 2:
The patent introduces an intermediary immersion interconnection structure that mediates between the first and second semiconductor devices. This intermediate conductive structure fills recesses and provides a stress-free bonding interface, enabling precise alignment of miniaturized features while maintaining productivity through a streamlined stacking process
3Reliability
If solder-based interconnections are used to connect contact pads between stacked devices, then electrical connections are established, but high-temperature processing and mechanical stress are required
Solution Approach 1:
The patent replaces the solder-based mechanical interconnection system with an immersion plating system. Conductive material is deposited electrolessly into recesses to form immersion interconnection structures, eliminating the need for high-temperature soldering processes while establishing reliable electrical connections between contact pads
Solution Approach 2:
The patent changes the processing temperature parameter from soldering temperatures (typically >200°C) to electroless plating temperatures (below 100°C). The immersion interconnection structure is formed through chemical deposition at low temperatures, eliminating thermal stress while maintaining electrical connection reliability
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 results in improved yield and cost savings by forming solderless immersion interconnections at low temperatures, enabling efficient high-density chip stacking with better alignment and reduced mechanical stress, thus addressing the limitations of existing packaging techniques.
Implementation Method 1
an immersion interconnection is formed between each of the plurality of first contact pads of the first semiconductor device and one of the plurality of second contact pads of the second semiconductor device
Data Source
AI summary
Semiconductor devices and methods of manufacture thereof are disclosed. In some embodiments, a method of manufacturing a device includes coupling a first semiconductor device to a second semiconductor device by spacers. The first semiconductor device has first contact pads disposed thereon, and the second semiconductor device has second contact pads disposed thereon. The method includes forming an immersion interconnection between the first contact pads of the first semiconductor device and the second contact pads of the second semiconductor device.