Area-Selective Metal Deposition for High Aspect Ratio Semiconductor Etching

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Current semiconductor fabrication methods face challenges in precisely controlling the patterning process, particularly in forming high aspect ratio structures like lower electrode holes and channel holes, due to etching failures caused by crystal grains in metal layers, which complicates the formation of desired shapes and increases process complexity.

Innovation Solution

The method involves forming a nonmetal deposition active layer and a guide pattern on a semiconductor substrate, followed by selective deposition of a metal-containing layer using an area-selective deposition method to create a metal mask, which allows for precise etching of the semiconductor layers without the need for a separate metal etching step, thereby overcoming etching failures and enabling the formation of desired patterns.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If metal layers are used as masks for etching, then the masking function is provided, but etching failures occur due to crystal grains in metal layers

Engineering Contradiction:

Improveetching reliabilityVSAvoidetching failures caused by crystal grains

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

A nonmetal deposition active layer is introduced as an intermediary between the guide pattern and the metal-containing layer. This nonmetal layer serves as a buffer that prevents crystal grain formation in the metal mask, thereby eliminating etching failures while maintaining the masking function. The nonmetal layer is selectively removed after metal deposition, allowing the metal-containing layer to serve as the final mask.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The nonmetal deposition active layer is formed in advance before depositing the metal-containing layer. This preliminary action creates a controlled interface that prevents crystal grain formation during subsequent metal deposition, ensuring reliable etching without failures.

Inventive Principle:

Principle #10Preliminary action

2Ease of manufacture

If conventional metal masking is used, then pattern formation is achieved, but process complexity increases due to separate metal etching steps

Engineering Contradiction:

Improvefabrication process simplicityVSAvoidnumber of etching steps

Core Design Contradiction:

Ease of manufactureVSDevice complexity

Solution Approach 1:

The harmful crystal grain formation is extracted and isolated to the nonmetal deposition active layer, which is selectively removed after metal deposition. This allows the metal-containing layer to serve purely as a mask without requiring separate metal etching steps, simplifying the overall fabrication process.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The nonmetal deposition active layer is temporarily introduced and then discarded after serving its purpose of preventing crystal grain formation. This temporary layer enables the metal-containing layer to function as an effective mask without requiring additional etching steps for metal removal.

Inventive Principle:

Principle #34Discarding and recovering

3Manufacturing precision

If area-selective deposition is used to form metal mask, then precise pattern control is achieved, but the deposition process complexity increases

Engineering Contradiction:

Improvepattern formation precisionVSAvoiddeposition process complexity

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The nonmetal deposition active layer is formed with specific local properties that enable selective metal deposition. This layer has different deposition characteristics compared to the guide pattern, allowing metal-containing layers to be deposited only in desired areas through area-selective deposition, achieving precise pattern control.

Inventive Principle:

Principle #3Local quality

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 enables the formation of high aspect ratio structures with improved precision and control, reducing the risk of etching failures and simplifying the fabrication process by eliminating the need for a metal etching step, while allowing for the use of metal layers as hard masks to form patterns in desired shapes.

Implementation Method 1

forming a metal mask pattern on the exposed surface of the deposition active layer using an area-selective deposition method

Methodology Applied

Scientific EffectArea-selective deposition: Physical Vapour Deposition

Implementation Method 2

forming a guide pattern on a semiconductor substrate such that the guide pattern delimits an exposed surface of the deposition active layer

Methodology Applied

Scientific EffectPhysical masking: Physical Containment

Implementation Method 3

sequentially etching the deposition active layer and the mold layer by using the metal mask pattern as an etch mask

Methodology Applied

Scientific EffectEtching: Ablation

Data Source

PatentUS10438802B2Method of fabricating a semiconductor device

Publication Date: 2019.10.08 SAMSUNG ELECTRONICS CO LTD

AI summary

A method of fabricating a semiconductor device, the method including forming a deposition active layer and a guide pattern on a semiconductor substrate such that the guide pattern delimits an exposed surface of the deposition active layer; and selectively depositing a metal-containing layer on the exposed surface of the deposition active layer exposed by the guide pattern, wherein the deposition active layer is a nonmetal layer.