Angled epitaxy cut
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Solution Overview
Problem
Current semiconductor fabrication methods face challenges in optimizing contact size for both frontside and backside contacts due to limitations in source/drain isolation, particularly with the use of straight epitaxy cuts which reduce the available interface area for contacts.
Innovation Solution
The introduction of an angled epitaxy cut to form an angled source/drain isolation pillar, which optimizes contact size by providing a longer interface area for both frontside and backside contacts, thereby enhancing electrical connectivity and reducing contact resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of moving object
If a straight epitaxy cut is used to form source/drain isolation pillars, then the fabrication process is simple, but the contact area for both frontside and backside contacts is reduced
Solution Approach 1:
The patent applies asymmetry by changing the isolation pillar structure from a straight vertical cut to an angled cut. This asymmetric geometry allows the pillar to provide effective isolation while simultaneously increasing the available contact area for both frontside and backside contacts, resolving the contradiction between simple fabrication and adequate contact area.
Solution Approach 2:
The patent introduces an angular dimension to the previously vertical isolation pillar. By cutting the epitaxy at an angle rather than straight down, the isolation pillar gains an additional geometric dimension that increases the interface area available for contacts without adding complex multi-layer structures.
2Reliability
If the contact area is increased to improve electrical connectivity, then contact resistance is reduced, but the isolation between source and drain regions becomes more difficult to achieve
Solution Approach 1:
The angled cut creates an asymmetric isolation pillar that naturally provides both isolation function and increased contact area. The slanted geometry allows the pillar to extend further laterally, improving electrical connectivity through larger contact interfaces while maintaining effective source/drain isolation through the angled barrier structure.
Solution Approach 2:
The patent applies local quality by creating different geometries at different locations. The angled isolation pillar provides enhanced contact area at the contact regions while maintaining effective isolation at the source/drain boundaries, optimizing both electrical connectivity and isolation performance in their respective locations.
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
The angled source/drain isolation pillar effectively increases the contact area for both frontside and backside contacts, leading to improved transport effects and device performance by maximizing the interface between source/drain regions and contacts.
Implementation Method 1
leveraging an angled epitaxy cut to provide an angled source/drain isolation pillar
Data Source
AI summary
Embodiments of the present disclosure are directed to processing methods and resulting structures that leverage an angled epitaxy cut to provide an angled source/drain isolation pillar that optimizes contact size for both frontside contacts and backside contacts. In a non-limiting embodiment, a semiconductor device includes a first source or drain (S/D) region and a second S/D region. The semiconductor device further includes an angled isolation pillar between the first S/D region and the second S/D region.