CNT Film Boron Nitride Liner for Microelectronic Reliability

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Solution Overview

Problem

The integration of carbon nano-tube (CNT) materials into microelectronic devices is challenging due to their rough surface topography and porosity, leading to difficulties in etching and increased fabrication costs, as well as the risk of short-circuiting and damage during metal deposition processes.

Innovation Solution

A method involving the formation of a CNT-based MIM structure with a boron nitride or carbon liner to protect the CNT material from infiltration and damage, using lower energy deposition techniques such as CVD, ALD, or e-beam evaporation for top electrode deposition, and incorporating a dielectric sidewall liner to prevent degradation during dielectric fill steps.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional metal deposition processes are used on CNT layers, then metal electrodes can be formed, but the rough surface topography and porosity of CNT material cause metal infiltration and short-circuiting

Engineering Contradiction:

Improvedevice reliabilityVSAvoidmetal infiltration and short-circuiting

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

A liner layer comprising aluminum oxide, aluminum nitride, boron nitride, or silicon nitride is introduced as an intermediary between the CNT material and the metal electrode. This liner prevents direct contact and infiltration of metal into the porous CNT structure, thereby eliminating short-circuiting while allowing electrical functionality to be maintained.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The liner layer is formed on the CNT material before the metal electrode deposition process. This preliminary protective action ensures that when metal is subsequently deposited, it cannot infiltrate the CNT pores, preventing short-circuits before they can occur during the manufacturing process.

Inventive Principle:

Principle #10Preliminary action

2Productivity

If high energy deposition techniques are used for top electrode formation, then efficient metal deposition is achieved, but the CNT material suffers from damage and degradation

Engineering Contradiction:

Improvedeposition efficiencyVSAvoidCNT material integrity

Core Design Contradiction:

ProductivityVSStrength

Solution Approach 1:

The liner layer serves as a protective cushion that absorbs and shields the CNT material from the high energy impact during metal deposition processes. This beforehand cushioning allows efficient deposition to proceed while preventing damage to the underlying CNT switching material.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

3Ease of manufacture

If standard fabrication processes are used for CNT-based devices, then manufacturing simplicity is maintained, but etching difficulties arise due to rough surface topography and porosity

Engineering Contradiction:

Improvefabrication simplicityVSAvoidetching precision

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The liner layer acts as an intermediary that provides a well-defined surface for subsequent fabrication processes. This liner with its controlled properties enables precise etching and patterning operations to be performed on top of it, overcoming the etching difficulties posed by the rough and porous CNT material beneath.

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

This approach reduces the risk of short-circuiting and damage to the CNT material, enhances the reliability of CNT-based memory devices by minimizing infiltration and penetration, and improves the overall fabrication process by using lower energy deposition methods, resulting in more stable and efficient microelectronic structures.

Implementation Method 1

forming a boron nitride layer above the CNT layer, wherein the boron nitride layer comprises: (1) a first portion disposed above the CNT layer; and/or (2) a second portion disposed in and/or around one or more carbon nano-tubes in the CNT layer

Methodology Applied

Scientific EffectPhysical barrier protection:

Implementation Method 2

using lower energy deposition techniques such as CVD, ALD, or e-beam evaporation for top electrode deposition

Methodology Applied

Scientific EffectVapor phase deposition: Deposition (physical)

Data Source

PatentUS8835892B2Electronic devices including carbon nano-tube films having boron nitride-based liners, and methods of forming the same

Publication Date: 2014.09.16 SANDISK TECHNOLOGIES LLC

AI summary

Methods in accordance with this invention form a microelectronic structure by forming a carbon nano-tube (“CNT”) layer, and forming a boron nitride layer (“BN liner”) above the CNT layer, wherein the BN liner comprises: (1) a first portion disposed above and in contact with the CNT layer; and/or (2) a second portion disposed in and/or around one or more carbon nano-tubes in the CNT layer. Numerous other aspects are provided.