Backside Power Rail Structure for Low-Loss Semiconductor Delivery
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
As semiconductor devices shrink, power delivery becomes increasingly inefficient due to electrical isolation issues and high resistance in metal layers, making it difficult to provide power without affecting device performance, and backside power delivery complicates manufacturing processes.
Innovation Solution
The implementation of backside power delivery systems, including a reconstituted element with a semiconductor die, insulating material, power rail, and interconnect structure, allows for efficient power delivery from the front surface to the back surface of the semiconductor die, reducing voltage drops and enabling thicker, shorter power lines with lower resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If power is delivered through frontside metal layers in shrinking semiconductor devices, then signal routing can be integrated with power delivery, but power delivery losses increase due to high resistance and electrical isolation issues
Solution Approach 1:
The patent introduces backside power delivery as a third-dimensional solution, routing power lines through the backside of the semiconductor device rather than through the frontside metal layers. This dimensional separation allows signal routing and power delivery to occupy different spatial dimensions, eliminating the trade-off between integration and power delivery efficiency. Power rails are established on the backside substrate, connecting to power vias that extend through the device thickness to reach frontside power contacts.
2Loss of energy
If backside power delivery is implemented, then power delivery losses are reduced and frontside congestion is alleviated, but manufacturing process complexity increases
Solution Approach 1:
The manufacturing process is segmented into distinct phases: frontside processing to create circuitry and power vias, backside processing to form power rails and interconnect structures, and final assembly to bond the sides together. This segmentation allows each subsystem to be optimized independently - the frontside for signal routing and the backside for power delivery - while simplifying the overall manufacturing by avoiding the need to route both signals and power through the same complex frontside metal layers.
3Loss of energy
If thicker, shorter power lines are used to reduce resistance, then power delivery efficiency improves, but device area increases
Solution Approach 1:
By moving power delivery to the backside dimension, the patent enables the use of thicker power rails with larger cross-sectional areas without increasing the device footprint. The backside substrate provides additional vertical space for accommodating lower-resistance power paths through the device thickness, achieving improved power delivery efficiency while maintaining the same planar device area.
Data Source
AI summary
An assembly may include a reconstituted element having a front surface and a back surface, the reconstituted element comprising: a semiconductor die having a front side and a back side, the semiconductor die including circuitry closer to the front side than to the back side and a via extending from the back side of the semiconductor die to connect to the circuitry, an insulating material disposed along a side surface of the semiconductor die, a power rail extending from the front surface to the back surface of the reconstituted element and configured to deliver power to the semiconductor die; and an interconnect structure configured to electrically connect the power rail to the via and to deliver power to the semiconductor die from the back side of the semiconductor die.