3D Semiconductor Metal Layer Layout for Heat Removal and Annealing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In 3D stacked integrated circuits, the degradation of wire performance with 'scaling' leads to increased power consumption and thermal resistance, and existing heat removal methods are inefficient, particularly due to high thermal resistance and damage from high-temperature annealing processes.
Innovation Solution
The implementation of a hybrid bonding method with a shield/heat sink layer and optical annealing to repair crystal lattice damage and enhance heat removal, using materials like tungsten and copper for thermal conductivity, and incorporating a global power distribution network with higher conductivity than local networks to facilitate efficient heat transfer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If high-temperature annealing is used to repair crystal lattice damage, then crystal lattice damage is repaired, but metal interconnects are damaged
Solution Approach 1:
A shield layer comprising a first portion and a second portion is introduced as an intermediary structure. The first portion is positioned between the annealing source and the metal interconnects to block harmful thermal radiation, while the second portion is positioned between the annealing source and the semiconductor layer to allow beneficial annealing. This mediator structure enables selective thermal protection, repairing crystal lattice damage while preventing metal interconnect damage.
2Loss of energy
If conventional heat removal methods are used, then heat is removed from 3D stacked ICs, but thermal resistance remains high and efficiency is low
Solution Approach 1:
The power distribution network is replicated across multiple levels in the 3D stacked IC structure. Each level contains both local power distribution networks and global power distribution networks that extend across the level. This copying of the power distribution architecture creates multiple parallel thermal conduction paths, effectively reducing thermal resistance and improving heat removal efficiency from the stacked device layers.
3Productivity
If wire scaling is continued to improve transistor performance, then transistor density increases, but wire performance degrades and power consumption increases
Solution Approach 1:
The patent transitions from 2D planar interconnect architecture to 3D stacked architecture with multiple levels of power distribution networks. By adding the vertical dimension with multiple stacked levels, the system achieves shorter wire lengths and reduced wiring delay while maintaining improved transistor density. The multi-level global and local power distribution networks provide efficient power delivery in the 3D space, overcoming the limitations of continued 2D wire scaling.
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 enables defect-free single crystalline semiconductor layers at low temperatures, reduces thermal resistance, and improves heat removal efficiency while preventing damage to metal interconnects, thereby enhancing the performance and reliability of 3D ICs.
Implementation Method 1
using materials like tungsten and copper for thermal conductivity, and incorporating a global power distribution network with higher conductivity than local networks to facilitate efficient heat transfer
Implementation Method 2
optical annealing to repair crystal lattice damage
Implementation Method 3
optical annealing to repair crystal lattice damage
Implementation Method 4
The implementation of a hybrid bonding method with a shield/heat sink layer
Data Source
AI summary
A 3D semiconductor device including: a first level with first transistors, single crystal layer overlaid by at least one first metal layer which includes interconnects between the first transistors forming first control circuits; the first metal layer(s) overlaid by a second metal layer which is overlaid by a second level which includes first memory cells which include second transistors, overlaid by a third level which includes second memory cells which include third transistors and are partially disposed over the control circuits, which control data written to second memory cells; and a fourth metal layer overlaying a third metal layer which overlays the third level; where third transistor gate locations are aligned to second transistor gate locations within less than 100 nm, and the average thickness of fourth metal layer is at least twice the average thickness of second metal layer; the fourth metal layer includes a global power distribution grid.