Contact Plug Fence Insulation Structure for Leakage Isolation

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Solution Overview

Problem

In highly integrated semiconductor devices, the close spacing of contact plugs leads to difficulty in maintaining electrical isolation, resulting in increased leakage currents due to electron and hole tunneling between adjacent plugs.

Innovation Solution

The semiconductor device incorporates a fence insulation structure with a first insulation pattern having a higher band gap than the second insulation pattern, which electrically insulates contact plug structures, reducing electron and hole tunneling and thereby minimizing leakage currents.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If contact plugs are closely spaced to increase integration density, then arrangement density is improved, but electrical isolation between contact plugs deteriorates

Engineering Contradiction:

Improvearrangement density of contact plugsVSAvoidelectrical isolation between contact plugs

Core Design Contradiction:

Quantity of substanceVSReliability

Solution Approach 1:

The insulation structure is divided into two distinct patterns: a first insulation pattern (e.g., silicon oxide) and a second insulation pattern (e.g., silicon nitride). This segmentation allows each layer to perform specific functions - the first layer provides baseline insulation while the second layer with higher band gap provides enhanced barrier against carrier tunneling, thereby maintaining electrical isolation even when contact plugs are closely spaced.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The insulation structure uses a composite of two different insulation materials with different band gap characteristics. The first insulation pattern (lower band gap) and second insulation pattern (higher band gap) are combined in a layered configuration, creating a composite structure that leverages the advantages of both materials to effectively block carrier tunneling while maintaining process compatibility.

Inventive Principle:

Principle #40Composite materials

2Quantity of substance

If distance between contact plugs is decreased to increase integration, then arrangement density is improved, but leakage current due to tunneling increases

Engineering Contradiction:

Improvearrangement density of contact plugsVSAvoidleakage current between contact plugs

Core Design Contradiction:

Quantity of substanceVSObject-generated harmful factors

Solution Approach 1:

The invention changes the critical parameter of band gap energy in the insulation structure. By introducing a second insulation pattern with a higher band gap than the first insulation pattern, the energy barrier for carrier tunneling is increased. This parameter change effectively reduces leakage current even when the physical distance between contact plugs is minimized for high integration density.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The dual-layer insulation structure acts as an intermediary barrier between adjacent contact plugs. The first insulation pattern provides initial isolation while the second insulation pattern with higher band gap serves as an enhanced mediator that specifically targets and blocks quantum tunneling of carriers, thereby reducing leakage current in highly integrated structures where plug spacing is minimal.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 implementation of a high-band gap insulation structure effectively decreases leakage currents between contact plugs, enhancing the electrical characteristics and reducing defects in the semiconductor device.

Implementation Method 1

The first insulation pattern may include a material having a band gap higher than a band gap of the second insulation pattern

Methodology Applied

Scientific EffectBand gap:

Implementation Method 2

leakage currents due to tunneling of holes and electrons between the adjacent contact plug structures

Methodology Applied

Scientific EffectTunneling:

Data Source

PatentUS12426245B2Semiconductor device

Publication Date: 2025.09.23 SAMSUNG ELECTRONICS CO LTD

AI summary

A semiconductor device may include contact plug structures on a substrate, and an insulation structure filling a space between the contact plug structures to insulate the contact plug structures from each other. The contact plug structures may be spaced apart from each other in a first direction. The insulation structure may include a first insulation pattern and a second insulation pattern. The second insulation pattern may include an insulation material having an etch selectivity with respect to silicon oxide. The first insulation pattern may contact a portion of sidewalls of the second insulation pattern and a portion of sidewalls of the contact plug structure. The first insulation pattern may include a material having a band gap higher than a band gap of the second insulation pattern.