Semiconductor Contact Plug Gap Cover Layer Design

Solution Overview

Problem

The increasing electric resistance between components of semiconductor devices due to down-scaling hinders fast operation speeds and reliability in semiconductor devices.

Innovation Solution

A semiconductor device design featuring a lower contact plug with a gap portion and a gap cover layer, and an upper contact plug with an upper cover layer, which reduces electric resistance by filling the gap and preventing voids and oxidation, thereby enhancing connection reliability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If down-scaling of semiconductor device is performed to achieve fast operation speed, then operation speed is improved, but electric resistance between components increases

Engineering Contradiction:

Improveoperation speedVSAvoidelectric resistance

Core Design Contradiction:

SpeedVSReliability

Solution Approach 1:

The contact plug is divided into multiple layers (lower plug layer, upper plug layer, gap cover layer, upper cover layer) with distinct functions. The lower plug layer provides electrical connection, while the gap cover layer and upper cover layer specifically address oxidation prevention, creating a segmented defense against electric resistance issues.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The gap cover layer is formed to fill the gap portion of the lower plug layer before the upper plug layer is deposited. This preliminary action prevents void formation and oxidation at the critical interface between lower and upper contact plugs, addressing potential reliability issues before they can manifest during device operation.

Inventive Principle:

Principle #10Preliminary action

2Ease of manufacture

If conventional contact plug structure is used, then manufacturing is simpler, but voids and oxidation occur increasing electric resistance

Engineering Contradiction:

Improvecontact plug fabricationVSAvoidelectric connection reliability

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The gap cover layer is formed to fill the gap portion of the lower plug layer before the upper plug layer is deposited. This preliminary action prevents void formation and oxidation at the critical interface between lower and upper contact plugs, addressing potential reliability issues before they can manifest during device operation.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The gap cover layer acts as an intermediary between the lower plug layer and the upper plug layer. It fills the gap portion and prevents oxidation, serving as a protective mediator that ensures reliable electrical connection while allowing the manufacturing process to proceed with standard deposition techniques.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Reliability

If gap portion exists in lower plug layer, then oxidation is prevented, but manufacturing complexity increases

Engineering Contradiction:

Improveoxidation preventionVSAvoidcontact plug structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The contact plug is divided into multiple layers (lower plug layer, upper plug layer, gap cover layer, upper cover layer) with distinct functions. The lower plug layer provides electrical connection, while the gap cover layer and upper cover layer specifically address oxidation prevention, creating a segmented defense against electric resistance issues.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The gap cover layer acts as an intermediary between the lower plug layer and the upper plug layer. It fills the gap portion and prevents oxidation, serving as a protective mediator that ensures reliable electrical connection while allowing the manufacturing process to proceed with standard deposition techniques.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS10741657B2Semiconductor devices and contact plugs

Publication Date: 2020.08.11 SAMSUNG ELECTRONICS CO LTD

AI summary

A semiconductor device has a high electric connection reliability and includes a base substrate having a connection target layer, a lower contact plug formed over the base substrate and electrically connected to the connection target layer, and an upper contact plug formed over the lower contact plug, wherein the lower contact plug includes a lower plug layer having a gap portion extending inward from a top portion of the lower plug layer, a gap cover layer filling the gap portion, and an upper cover layer covering a top surface of the lower plug layer.