Source/Drain Contact Isolation Slopes for Nanosheet Contact Reliability
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Solution Overview
Problem
Existing semiconductor devices face challenges in ensuring reliable contact formation in the source/drain regions, which can affect the performance and reliability of integrated circuit devices.
Innovation Solution
The semiconductor device incorporates a specific structure with a lower interlayer insulating layer, active pattern, gate electrodes, source/drain regions, liner layers, and contact isolation layers, featuring distinct slope profiles in the sidewalls of the contact isolation layers to enhance the electrical connection and reliability of the source/drain contacts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional contact structures are used in multi-gate transistors, then manufacturing is simpler, but contact reliability in source/drain regions deteriorates
Solution Approach 1:
The contact structure is divided into multiple portions: a first portion extending from the upper surface of the lower interlayer insulating layer to contact the source/drain region, and a second portion extending into the source/drain region, liner layer, and active pattern. This segmentation allows each portion to be optimized for its specific function, improving overall contact reliability while managing complexity through functional division.
Solution Approach 2:
The contact isolation layer is designed with asymmetric slope profiles where the first sidewall has a different slope than the second sidewall. This asymmetric geometry optimizes the contact interface for reliable electrical connection while maintaining manufacturability through controlled deposition and etching processes.
2Reliability
If source/drain contact reliability is improved through complex structures, then contact performance increases, but manufacturing difficulty increases
Solution Approach 1:
The contact isolation layer is formed beforehand with specific slope profiles before the contact is created. This preliminary structuring prepares the interface for optimal contact formation, ensuring reliable electrical connection while simplifying the subsequent contact fabrication process through pre-configured geometry.
Solution Approach 2:
The slope profiles of the contact isolation layer sidewalls are controlled as specific geometric parameters, with the first sidewall having a different slope than the second sidewall. By optimizing these geometric parameters during manufacturing, contact reliability is improved while maintaining compatibility with standard fabrication processes.
Data Source
AI summary
A semiconductor device includes a lower interlayer insulating layer, an active pattern spaced, a plurality of nanosheets, a gate electrode, a source/drain region, a liner layer, a contact isolation layer, and a source/drain contact, where the sidewall of the contact isolation layer includes a first sidewall in contact with the source/drain contact in the first horizontal direction, a second sidewall in contact with each of the liner layer and the active pattern in the first horizontal direction, and a vertex between the first sidewall and the second sidewall, and where a slope profile of the first sidewall of the contact isolation layer and a slope profile of the second sidewall of the contact isolation layer are different.