Source/Drain Contact Structure With Concave Sidewalls for Dense Integration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The challenge in semiconductor manufacturing is to create highly integrated devices while reducing fabrication costs, which involves shrinking device size and increasing the density of structures without compromising performance or introducing defects.
Innovation Solution
The semiconductor device design includes a source/drain contact structure with a lower contact extending in one direction and an upper contact structure protruding from it, featuring sidewalls with concave sub-sidewalls and apex parts, along with a contact insulating liner, to enhance connectivity and prevent short circuits, and a method of fabricating this structure involves forming recesses and insulating liners to optimize contact formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If device size is shrunk to increase integration density, then integration density improves, but manufacturing precision requirements worsen
Solution Approach 1:
The contact structure is divided into multiple sub-sidewalls (first sub-sidewalls, second sub-sidewalls) with different orientations and functions. This segmentation allows each sub-sidewall to be formed with controlled precision using specific etching processes, thereby managing the overall manufacturing precision challenge while achieving high integration density through the multi-component contact structure.
Solution Approach 2:
The contact structure transitions from a simple planar contact to a three-dimensional structure with upper and lower contact structures, multiple sub-sidewalls, and apex parts. This dimensional complexity allows for better electrical connectivity and stress management in highly integrated devices without proportionally increasing the footprint, thus improving integration density while distributing manufacturing precision requirements across multiple geometric features.
2Ease of manufacture
If device size is shrunk to reduce fabrication cost, then fabrication cost improves, but device complexity increases
Solution Approach 1:
The contact structure is segmented into distinct components (lower contact structure, upper contact structure, multiple sub-sidewalls, apex parts) that can be formed using standard semiconductor fabrication processes. This segmentation allows each component to be optimized independently while using existing manufacturing capabilities, thereby managing device complexity without proportionally increasing fabrication cost.
Solution Approach 2:
The contact structure utilizes parameter variations in the etching process to create different sub-sidewall orientations and apex part geometries. By controlling etching conditions (anisotropic vs. isotropic, etch selectivity, etch depth), the complex three-dimensional contact structure is formed using standard process parameters rather than requiring new fabrication techniques, thus managing complexity while controlling fabrication cost.
3Ease of manufacture
If contact structure is simplified to reduce manufacturing steps, then ease of manufacture improves, but short circuit prevention capability worsens
Solution Approach 1:
The contact structure is segmented into multiple sub-sidewalls with different orientations that naturally create physical barriers and insulation pathways. This segmentation provides inherent short circuit prevention through the geometric configuration itself, eliminating the need for additional complex insulation layers or manufacturing steps while maintaining reliability.
Solution Approach 2:
The apex parts serve as intermediary elements between the upper and lower contact structures, providing controlled transition zones that prevent direct short circuits. These apex parts act as mediators that manage electrical field distribution and provide natural insulation pathways, thereby preventing short circuits without requiring additional manufacturing complexity.
Data Source
AI summary
A semiconductor device includes a source/drain pattern disposed on a substrate and a source/drain contact connected to the source/drain pattern. The source/drain contact includes a lower contact structure extending in a first direction and an upper contact structure protruding from the lower contact structure. The upper contact structure includes a first sidewall and a second sidewall facing away from each other in the first direction. The first sidewall of the upper contact structure includes a plurality of first sub-sidewalls, and each of the first sub-sidewalls includes a concave surface.