Frontside and Backside Power Rails for Multi-Voltage IC Routing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing semiconductor fabrication methods face challenges in forming power rails on both the frontside and backside of integrated circuits, leading to increased voltage drop and power consumption as circuits scale down, particularly when implementing multiple voltage domains.
Innovation Solution
The implementation of frontside and backside power rails on semiconductor devices, where the frontside rail supplies one voltage domain and the backside rail supplies another, allowing for interleaving of power rails without competing for routing area and reducing resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If power rails are scaled down with the integrated circuit, then circuit density increases, but voltage drop across power rails increases and power consumption increases
Solution Approach 1:
The patent introduces a third dimension by forming power rails on both the frontside and backside of the substrate. This vertical stacking approach allows power distribution in the z-direction, effectively adding another dimension to the traditional planar power rail configuration. The backside power rails are electrically connected to frontside power rails through conductive paths (such as through-substrate vias), creating a three-dimensional power distribution network that reduces current density and voltage drop while maintaining high circuit density.
2Adaptability or versatility
If multiple voltage domains are implemented, then circuit functionality improves, but routing complexity and area competition increase
Solution Approach 1:
The patent segments the power distribution system into multiple independent voltage domains, with each domain having its own dedicated power rails and conductive paths. The substrate is divided into first and second regions with corresponding frontside and backside power rails for each region. This segmentation allows different voltage domains to be routed independently without interfering with each other, reducing routing complexity while supporting multiple voltage domains.
Solution Approach 2:
By utilizing both frontside and backside of the substrate for power rail configuration, the patent creates vertical separation between different voltage domains. This three-dimensional arrangement allows multiple voltage domains to coexist without competing for the same planar routing space, effectively resolving the area competition issue while maintaining routing simplicity.
3Ease of manufacture
If power rails are formed only on the frontside, then manufacturing process is simple, but voltage drop and power consumption increase
Solution Approach 1:
The patent extends the power rail configuration from a two-dimensional frontside-only layout to a three-dimensional structure by adding backside power rails. The backside power rails are formed using additional metal layers and conductive paths that traverse through or across the substrate. This vertical extension effectively doubles the power distribution capacity, reducing voltage drop and power consumption while maintaining compatibility with existing semiconductor manufacturing processes.
Data Source
AI summary
A semiconductor device includes transistors formed in a substrate. The transistors form at least a first cell functioning under a first power supply voltage, a second cell functioning under a second power supply voltage that is different from the first power supply voltage, and a third cell functioning under both the first power supply voltage and the second power supply voltage. The semiconductor device also includes a frontside power rail disposed on a frontside of the substrate and a backside power rail disposed on a backside of the substrate. The frontside power rail provides the first power supply voltage to the first cell and the third cell. The backside power rail provides the second power supply voltage to the second cell and the third cell.