Plasma Processing Gas Distribution for Uniform Etch

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Solution Overview

Problem

Plasma processing systems face challenges in achieving uniform etch rates across substrates with varying topography and in minimizing contamination and chamber memory effects, leading to non-uniform photoresist profiles and increased cleaning frequencies.

Innovation Solution

An enhanced plasma processing system with a top electrode temperature control system and differential plasma gas injection, allowing for asymmetric O2 distribution and reduced contamination by heating the electrode to increase collisions between oxygen ions and inert gas molecules, thereby optimizing the etch process and reducing contaminants.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single gas distribution system is used for the entire substrate, then the device complexity is reduced, but the manufacturing precision of etch rate uniformity deteriorates

Engineering Contradiction:

Improvegas distribution system complexityVSAvoidetch rate uniformity

Core Design Contradiction:

Device complexityVSManufacturing precision

Solution Approach 1:

The gas distribution system is divided into multiple independent zones (first plurality of zones and second plurality of zones) with separate gas distribution channels for each zone. This segmentation allows independent control of gas flow to different regions of the substrate, enabling precise adjustment of etch rates across the substrate surface while maintaining a manageable system architecture.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different gas flow rates are supplied to different zones based on local requirements. The system adjusts gas flow distribution locally to account for variations in substrate topography and etch characteristics across different regions, achieving uniform etch rates without requiring complete system redesign.

Inventive Principle:

Principle #3Local quality

2Manufacturing precision

If substrate processing is performed in multiple chambers with transfer, then the manufacturing precision of photoresist profile uniformity is improved, but the productivity and loss of time increase

Engineering Contradiction:

Improvephotoresist profile uniformityVSAvoidprocessing throughput

Core Design Contradiction:

Manufacturing precisionVSProductivity

Solution Approach 1:

Multiple processing functions that previously required separate chambers are merged into a single plasma processing chamber. The zoned gas distribution system enables different processing conditions to be created simultaneously in different zones, allowing diverse processing steps to be performed in one chamber without substrate transfer, thereby maintaining precision while improving productivity.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The single plasma processing chamber is designed to perform multiple processing functions simultaneously through zoned gas distribution. Different gas compositions and flow rates in different zones enable the chamber to handle various processing requirements (etching, deposition, cleaning) in one location, making the system universal and eliminating the need for multiple specialized chambers.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Ease of operation

If conventional gas distribution is used, then the ease of operation is maintained, but the manufacturing precision of etch uniformity across varying topography deteriorates

Engineering Contradiction:

Improvesystem operation simplicityVSAvoidetch uniformity

Core Design Contradiction:

Ease of operationVSManufacturing precision

Solution Approach 1:

The gas distribution system incorporates dynamic control capabilities with independent gas flow control for each zone. This allows the system to adapt gas flow rates in real-time based on processing requirements and substrate conditions, achieving precise etch uniformity control while maintaining operational flexibility through programmable control.

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 ensures more uniform etch rates across substrates, reduces contamination, and allows for more processing steps in a single chamber without substrate transfer, improving yield and reducing cleaning frequencies and costs.

Implementation Method 1

heating the electrode to increase collisions between oxygen ions and inert gas molecules

Methodology Applied

Scientific EffectThermal heating: Heating

Implementation Method 2

plasma processing system for processing a substrate

Methodology Applied

Scientific EffectPlasma: Plasma

Data Source

PatentUS7662723B2Methods and apparatus for in-situ substrate processing

Publication Date: 2010.02.16 LAM RES CORP

AI summary

A plasma processing system for processing a substrate is disclosed. The plasma processing system includes a gas distribution system. The plasma processing system also includes a gas flow control assembly coupled to the gas distribution system and configured to control a set of input gases provided by the gas distribution system. The plasma processing system further includes a first set of nozzles coupled to the gas flow control assembly and configured to supply a first set of gases for processing a first portion of the substrate. The plasma processing system further includes a second set of nozzles coupled to the gas flow control assembly and configured to supply a second set of gases for processing a second portion of the substrate.