Multiple Patterning Plasma Deposition for Low-Stress Spacers

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Solution Overview

Problem

Traditional photoresist techniques struggle to form precise patterns on substrates as device sizes decrease, leading to unwanted variations and leaning of patterned structures during etching, which affects subsequent pattern transfer.

Innovation Solution

A method involving a multiple patterning process using a cyclical deposition process with specific plasma power frequencies, inert gas ratios, and oxygen-free gas treatment to form patterned structures with high hardness and low stress, allowing for precise pattern transfer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If traditional photoresist techniques are used for patterning, then the process is simple and straightforward, but the manufacturing precision deteriorates as device sizes decrease, causing unwanted variation and leaning of patterned structures

Engineering Contradiction:

Improvepattern precisionVSAvoidpatterning process complexity

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patterning process is divided into multiple sequential steps (first pattern formation, spacer deposition, pattern transfer, second pattern formation) to achieve higher precision than single-step photolithography can provide for small device sizes

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Patterned structures are formed in advance as spacers before the final etching step, allowing precise positioning and reducing variation during subsequent processing

Inventive Principle:

Principle #10Preliminary action

2Manufacturing precision

If patterned structures are formed using conventional methods, then the process is easier to implement, but the stress in the patterned structures increases causing leaning and pattern distortion

Engineering Contradiction:

Improvepattern transfer accuracyVSAvoidpatterned structure stress

Core Design Contradiction:

Manufacturing precisionVSStress or pressure

Solution Approach 1:

The deposition parameters are optimized to control film stress, and the spacer thickness is carefully controlled to minimize stress-induced leaning while maintaining pattern fidelity

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The structure comprises multiple material layers (patterned photoresist, deposited spacer material, underlying substrate) with different mechanical properties that work together to reduce overall stress and prevent leaning

Inventive Principle:

Principle #40Composite materials

3Productivity

If the etch rate of patterned structures is increased for faster processing, then the productivity improves, but the manufacturing precision deteriorates due to greater pattern distortion

Engineering Contradiction:

Improveetching speedVSAvoidpattern transfer precision

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The etch rate is optimized by adjusting process parameters to achieve a balance between processing speed and pattern fidelity, ensuring precise pattern transfer without excessive distortion

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patterned structures are prepared in advance with optimized mechanical properties and stress states, allowing for controlled etching at appropriate rates without causing leaning or distortion during the etching process

Inventive Principle:

Principle #10Preliminary action

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 method produces patterned structures with desired mechanical properties, enabling precise pattern transfer and reliable device manufacturing by reducing stress and etch rate, thus minimizing pattern distortion.

Implementation Method 1

The step of forming the layer can include providing a precursor to the reaction chamber for a precursor pulse period, providing a reactant to the reaction chamber for a reactant pulse period

Methodology Applied

Scientific EffectChemical Vapor Deposition: Chemical Vapour Deposition

Implementation Method 2

applying at least one of a first plasma power, having a first frequency less than 1 MHz for a first plasma power period, and a second plasma power, having a second frequency, for a second plasma power period

Methodology Applied

Scientific EffectPlasma: Plasma

Implementation Method 3

When the ratio of inert gas to the reactant is greater than or equal to 2, desired mechanical properties (e.g., hardness and low stress) can be maintained

Methodology Applied

Scientific EffectGas phase treatment:

Data Source

PatentUS20230395372A1Method and system for forming patterned structures using multiple patterning process

Publication Date: 2023.12.07 ASM IP HLDG BV

AI summary

Methods of forming patterned structures suitable for a multiple patterning process and manipulating film properties are disclosed. Exemplary methods include forming a layer overlying the substrate, followed by treating the layer, wherein the layer is formed by providing a precursor to the reaction chamber for a precursor pulse period, providing a reactant to the reaction chamber for a reactant pulse period, applying a first plasma power having a first frequency for a first plasma power period, and optionally applying a second plasma power having a second frequency for a second plasma power period, wherein the first frequency is different than the second frequency. Exemplary methods can further include a step of treating the deposited material.