Stacked-Channel Contact Plug Geometry for Easier Opening Formation

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Solution Overview

Problem

The challenge in manufacturing semiconductor devices with vertically stacked channels is the difficulty in forming openings with reduced diameters due to increased integration, which complicates the process.

Innovation Solution

A semiconductor device design featuring an active pattern, gate structure, channels, and contact plugs with specific epitaxial layers and configurations, allowing for the formation of contact plugs that contact the epitaxial layers over a large area by adjusting minor process conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If the integration degree of semiconductor devices increases, then the number of vertically stacked channels increases, but the opening diameter is reduced making the formation process more challenging

Engineering Contradiction:

Improvenumber of channelsVSAvoidopening formation difficulty

Core Design Contradiction:

Quantity of substanceVSManufacturing precision

Solution Approach 1:

The contact plug is divided into three distinct portions (lower, middle, upper) with different cross-sectional area profiles. The middle portion has a cross-sectional area that increases from bottom to top, while the lower and upper portions have substantially constant cross-sectional areas. This segmentation allows each portion to serve different functional purposes in the formation process

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The contact plug transitions from a simple vertical structure to a three-dimensional structure with varying cross-sectional areas. The middle portion's expanding geometry adds a dimensional aspect that facilitates the opening formation process by providing a gradual transition zone

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Manufacturing precision

If the opening diameter is reduced, then the integration degree increases, but the process for forming the opening becomes more challenging

Engineering Contradiction:

Improveopening diameter controlVSAvoidopening formation process

Core Design Contradiction:

Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The contact plug structure is designed in advance with a middle portion that has an increasing cross-sectional area from bottom to top. This preliminary geometric configuration facilitates the subsequent opening formation process by providing a built-in expansion zone that makes it easier to create the required opening

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The cross-sectional area of the contact plug is varied along its height, with the middle portion transitioning from a smaller area at the bottom to a larger area at the top. This parameter change creates a favorable geometry for opening formation while maintaining precise diameter control

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS12550392B2Semiconductor devices

Publication Date: 2026.02.10 SAMSUNG ELECTRONICS CO LTD

AI summary

A semiconductor device includes an active pattern disposed on a substrate; a gate structure disposed on the active pattern; channels disposed on the substrate and that are spaced apart from each other in a vertical direction substantially perpendicular to an upper surface of the substrate; a first epitaxial layer disposed on a portion of the active pattern adjacent to the gate structure; and a contact plug disposed on the first epitaxial layer. The contact plug includes a lower portion; a middle portion disposed on the lower portion, where the middle portion has a width that increases from a bottom to a top thereof along the vertical direction; and an upper portion disposed on the middle portion.