Hardmask Layer and Temperature Tuning for Etch Uniformity

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Solution Overview

Problem

Existing semiconductor manufacturing processes face challenges in achieving precise and uniform etch geometry, leading to issues such as pattern distortion, dimension inaccuracy, under-etching, over-etching, poor selectivity, process integration issues, variability, and yield loss due to non-uniform etching of hardmasks.

Innovation Solution

The method involves forming a hardmask with a multi-layer structure, including an initiation layer and a carbon layer, and adjusting the deposition temperature to optimize the critical dimension (CD) etch profile, ensuring straight sidewalls in underlying material layers by modifying the etch profile of the hardmask.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a standard hardmask deposition process is used, then the manufacturing process is simple, but the etch geometry uniformity is poor leading to pattern distortion and dimension inaccuracy

Engineering Contradiction:

Improveetch geometry uniformityVSAvoidhardmask structure complexity

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The hardmask is divided into multiple functional layers: a first hardmask layer deposited at a first temperature and a second hardmask layer deposited at a second temperature. This segmentation allows each layer to contribute differently to the overall etch profile, with the first layer providing base coverage and the second layer optimizing the etch geometry for straight sidewalls and uniform patterns.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the hardmask structure are given different properties through temperature-controlled deposition. The first hardmask layer deposited at the first temperature provides different etch resistance characteristics compared to the second hardmask layer deposited at the second temperature, creating local quality variations that optimize the overall etch profile and geometry uniformity.

Inventive Principle:

Principle #3Local quality

2Manufacturing precision

If deposition temperature is adjusted to optimize CD etch profile, then etch uniformity improves, but process complexity increases

Engineering Contradiction:

Improvecritical dimension etch profileVSAvoiddeposition process complexity

Core Design Contradiction:

Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The deposition temperature parameter is changed between layers to optimize the critical dimension etch profile. The first hardmask layer is deposited at a first temperature while the second hardmask layer is deposited at a second temperature, creating different etch rates and profiles that collectively achieve the desired CD uniformity and straight sidewalls.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The deposition process is made dynamic by adjusting temperature parameters during sequential layer deposition. The system transitions from a static single-temperature process to a dynamic multi-temperature process, allowing optimization of the etch profile at different stages of hardmask formation.

Inventive Principle:

Principle #15Dynamics

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 enhances etch uniformity, resulting in consistent semiconductor device performance and higher manufacturing yield by creating straight sidewalls in underlying material layers, improving the precision and reliability of semiconductor devices.

Implementation Method 1

forming an initiation layer on a dielectric film in a first pass, forming a carbon layer on the initiation layer in a second pass

Methodology Applied

Scientific EffectPhysical Vapour Deposition: Physical Vapour Deposition

Implementation Method 2

etching the HM to a top surface of the dielectric film, and etching the dielectric film to create a plurality of pillars with straight sidewalls

Methodology Applied

Scientific EffectChemical Etching:

Data Source

PatentUS20250357137A1Deposition film tuning and temperature tuning for etch uniformity

Publication Date: 2025.11.20 APPLIED MATERIALS INC

AI summary

Aspects generally relate to methods and systems for optimizing a critical dimension (CD) etch profile of a hardmask (HM) to create etch uniformity for underlying material layers. The method includes forming an initiation layer on a dielectric film in a first pass, forming a carbon layer on the initiation layer in a second pass, the initiation layer and the carbon layer collectively defining a hardmask (HM), and the initiation layer configured to adjust a critical dimension (CD) etch profile of the HM, etching the HM to a top surface of the dielectric film, and etching the dielectric film to create a plurality of pillars with straight sidewalls. Adjusting the CD etch profile of the HM results in substantially straight HM sidewall openings. Further, formation of the substantially straight HM sidewall openings cause the plurality of pillars to have straight sidewalls.