3D Semiconductor Metal Layer Structure for Heat Dissipation
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Solution Overview
Problem
Existing 3D stacked integrated circuits face challenges in heat removal due to high power density and thermal resistance, with conventional methods like liquid coolant passage and thermal vias being inefficient, and high-temperature processing damaging underlying devices.
Innovation Solution
The implementation of a 3D semiconductor device with crystalline silicon layers, oxide-to-oxide and metal-to-metal bonds, and integrated temperature sensors, along with advanced metallization layers and via structures, enhances heat dissipation and protects sensitive circuit elements from processing heat.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If conventional heat removal methods (liquid coolant passages or thermal vias) are used in 3D stacked ICs, then heat dissipation is attempted, but thermal resistance remains high and heat removal efficiency is insufficient
Solution Approach 1:
The patent transitions from conventional 2D heat dissipation methods to 3D thermal management by implementing heat removal pathways that extend through the vertical dimension of stacked device levels. Thermal conductive materials are integrated between stacked devices to conduct heat away from high-power-density regions in the vertical direction, effectively utilizing the third dimension for heat transport and reducing overall thermal resistance in the 3D IC structure.
2Manufacturing precision
If high-temperature processing is used to manufacture 3D ICs, then crystalline silicon layers can be formed, but underlying devices and metal interconnects are damaged by processing heat
Solution Approach 1:
The patent introduces a heat shield layer as an intermediary component positioned between the crystalline silicon layer being processed and the underlying metal interconnect layers. This heat shield absorbs and blocks processing heat during high-temperature manufacturing steps, protecting the temperature-sensitive metal interconnects and underlying devices while allowing the crystalline silicon layer to be properly formed and annealed.
Solution Approach 2:
The heat shield is strategically positioned only in regions where underlying metal interconnects and devices are present and vulnerable to heat damage. This localized approach allows high-temperature processing to proceed in areas requiring crystalline silicon formation while protecting only the specific regions that need thermal protection, optimizing both manufacturing precision and heat protection.
3Productivity
If 3D stacking is implemented to reduce wire lengths, then transistor density increases, but heat generation from high power density exacerbates thermal management challenges
Solution Approach 1:
Thermal conductive materials are introduced as intermediary elements between stacked device levels, acting as heat sinks and thermal pathways. These materials conduct heat away from high-power-density transistor regions to lower levels or external heat sinks, managing the thermal load generated by increased transistor density while maintaining the benefits of 3D stacking for reduced wire lengths and improved productivity.
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 effectively manages heat in 3D ICs, reducing thermal resistance and protecting underlying devices, while enabling innovative IC devices with reduced development costs and improved yield.
Implementation Method 1
the bonded includes oxide to oxide bond regions
Implementation Method 2
the bonded includes metal to metal bond regions
Implementation Method 3
at least one temperature sensor
Implementation Method 4
enhances heat dissipation and protecting underlying devices
Data Source
AI summary
A semiconductor device including: a first level including: a first silicon layer including a first single crystal silicon; a first metal layer disposed over the first silicon layer; a second metal layer disposed over the first metal layer; a second level including a second single crystal silicon and a plurality of transistors, the second level is disposed over the second metal layer; a third metal layer disposed over the second level; a fourth metal layer disposed over the third metal layer; a via disposed through the second level, where the via has a diameter of less than 450 nm, where the second level thickness is less than four microns; and at least one temperature sensor.