Backside Source/Drain Contact Layout for Lower IR Drop
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Solution Overview
Problem
As semiconductor devices become increasingly highly integrated, voltage drop (IR drop) in the power distribution network (PDN) supplying power to integrated circuits becomes a significant issue, affecting the reliability, speed, and functionality of these devices.
Innovation Solution
The semiconductor device incorporates a back side power delivery network (BSPDN) with a back side source/drain contact that extends along the side face of the source/drain pattern, connected to a back side wiring structure through a first pillar and a wrapping part that protrudes beyond the upper face of the pillar, and is in contact with an etch stop layer, enhancing power distribution efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the width of wiring patterns and via patterns is decreased to achieve higher integration, then the integration level increases, but voltage drop (IR drop) in the power distribution network increases
Solution Approach 1:
The patent introduces a back side source/drain contact that extends along the side face of the source/drain pattern, adding a vertical/dimensional component to the power delivery path. This three-dimensional contact structure allows power to be delivered from the back side of the substrate, effectively adding another dimension to the power distribution network and reducing reliance on planar wiring patterns.
Solution Approach 2:
The etch stop layer serves as an intermediary element that the back side source/drain contact interacts with. The contact extends to contact the etch stop layer, which provides a stable interface for the vertical contact structure, enabling effective power transfer from the back side to the active regions without directly interfacing with the source/drain pattern.
2Productivity
If the wiring pattern width is decreased to supply power to highly integrated circuits, then more circuits can be integrated, but the power distribution efficiency deteriorates
Solution Approach 1:
The back side source/drain contact structure transitions the power delivery approach from two-dimensional planar wiring to three-dimensional vertical contact, enabling shorter and more direct power delivery paths that improve distribution efficiency without compromising integration density.
Solution Approach 2:
The power delivery function is segmented into separate components: the back side source/drain contact for vertical power delivery, the etch stop layer for structural support and interface, and the source/drain pattern for horizontal connection. This segmentation allows each component to be optimized independently for its specific function.
Data Source
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AI summary
Provided is a semiconductor device including: a substrate; an active pattern on an upper side of the substrate; a gate structure on and intersecting the active pattern ; a source/drain pattern on a side face of the gate structure and connected to the active pattern; an etch stop layer extending along an upper side of the substrate and an outer face of the source/drain pattern; a back side source/drain contact in the substrate, the back side source/drain contact being connected to the source/drain pattern; and a back side wiring structure on a lower side of the substrate and connected to the back side source/drain contact, wherein the back side source/drain contact extends along a part of a side face of the source/drain pattern, and wherein a part of the back side source/drain contact farthest from the lower side of the substrate is in contact with the etch stop layer.