Backside Power Rail Geometry for Reliable IC Power Delivery
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Solution Overview
Problem
Existing integrated circuit devices face challenges in reliably transmitting power to highly integrated elements due to inefficiencies in their power delivery networks.
Innovation Solution
The integrated circuit device incorporates a power delivery network with a substrate having a fin-type active region and a substrate recess, along with isolation films, source/drain regions, contact plugs, backside power rails, and via power rails, where the side surfaces of the backside and via power rails form an obtuse angle at their connection point.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional power delivery networks are used in highly integrated circuit devices, then device integration density increases, but power transmission reliability deteriorates
Solution Approach 1:
The patent transitions from conventional planar power delivery to a three-dimensional configuration by forming via power rails that extend vertically through the substrate and connect to backside power rails on the opposite surface. This vertical dimension enables more efficient power distribution to highly integrated elements without increasing lateral footprint, thereby maintaining power transmission reliability while supporting higher integration density.
Solution Approach 2:
The via power rails are formed within recesses of the substrate, creating a nested structure where the conductive via rails are embedded in the substrate material. This nesting approach allows the power delivery network to occupy space within the substrate volume rather than requiring additional lateral space, supporting high integration density while maintaining reliable power transmission through the embedded conductive paths.
2Ease of manufacture
If power rails are connected directly without optimized geometry, then manufacturing process is simpler, but electrical connection reliability deteriorates
Solution Approach 1:
The patent optimizes the geometric parameters of the via power rails by controlling the angles between their side surfaces to form an obtuse angle configuration. This parameter change in the structural geometry enhances the filling efficiency and electrical contact area between via power rails and backside power rails, thereby improving electrical connection reliability while remaining compatible with existing manufacturing processes.
Solution Approach 2:
The patent applies different geometric characteristics to different regions of the via power rails. The side surfaces of the via power rails are configured with specific angles relative to the substrate surfaces, creating localized geometric optimization at the connection points with backside power rails. This local geometric quality enhancement ensures reliable electrical connection without complicating the overall manufacturing process.
Data Source
AI summary
An integrated circuit device includes a substrate having a front side and a back side opposite to the front side and including a fin-type active region in the front side and a substrate recess in the back side, an isolation film in the substrate defining the fin-type active region, a source/drain region on the fin-type active region, a contact plug above the substrate, a backside power rail at least partially filling the substrate recess, and a via power rail electrically connected to the contact plug, the via power rail extending into the isolation film and connected to the backside power rail. A side surface of the backside power rail and a side surface of the via power rail form an obtuse angle at a portion where the backside power rail is connected to the via power rail.