Subatmospheric PEALD Narrow Gap Electrodes Sidewall Conformality
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Solution Overview
Problem
Conventional plasma-enhanced atomic layer deposition (PEALD) faces challenges in achieving uniform film properties, particularly chemical resistance and dry etching resistance, on the sidewalls of fine trenches due to uneven ion bombardment, which are inferior to those on flat surfaces.
Innovation Solution
The method involves generating thermal plasma at subatmospheric pressure using capacitively coupled electrodes with a narrowed gap of 5 mm or less, allowing for improved film deposition on sidewalls by increasing process pressure and using a flow-pass system for continuous precursor and reactant supply, enhancing ion bombardment and conformality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional PEALD uses low pressure (1 to 10 mTorr) and large electrode gap (1 to 5 cm), then plasma can be generated easily, but ion bombardment is weaker at sidewalls resulting in inferior film properties
Solution Approach 1:
The patent changes the pressure parameter from conventional low pressure (1-10 mTorr) to subatmospheric pressure (15-80 kPa), and adjusts the electrode gap from 1-5 cm to 5 mm or less. These parameter changes enable sufficient ion bombardment at sidewalls while maintaining plasma generation, resolving the contradiction between film property reliability and manufacturing precision.
2Manufacturing precision
If process pressure is increased to subatmospheric level with narrowed electrode gap, then ion bombardment uniformity improves, but plasma generation becomes more difficult
Solution Approach 1:
The patent applies dynamic control by adjusting the electrode gap to 5 mm or less during the deposition process. This dynamic adjustment enables plasma generation at subatmospheric pressure (15-80 kPa) while maintaining uniform ion bombardment, resolving the contradiction between manufacturing precision and ease of manufacture.
3Productivity
If conventional PEALD is used for carbon-based films, then deposition can proceed, but conformality is poor due to insufficient ion bombardment at sidewalls
Solution Approach 1:
The patent changes the pressure parameter to subatmospheric (15-80 kPa) and electrode gap to 5 mm or less, enabling sufficient ion bombardment at sidewalls during carbon-based film deposition. This resolves the contradiction between productivity and manufacturing precision by achieving both deposition capability and improved conformality.
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 significantly improves the properties of films deposited on sidewalls, making them comparable to those on flat surfaces, including wet etch resistance, and enhances conformality, especially for carbon-based films which typically show poor conformality.
Implementation Method 1
applying RF power for glow discharge in a pulse to one of the parallel plate electrodes
Implementation Method 2
thermal plasma is generated by PEALD at subatmospheric pressure using a conventional or any suitable capacitively coupled plasma (CCP) apparatus
Implementation Method 3
PEALD uses a self-limiting adsorption reaction process
Data Source
AI summary
A method for depositing a film by plasma-enhanced subatmospheric-pressure atomic layer deposition (subatmospheric PEALD) is conducted using capacitively coupled parallel plate electrodes with a gap of 1 mm to 5 mm, wherein one cycle of subatmospheric PEALD includes: supplying a precursor in a pulse to the reaction chamber; continuously supplying a reactant to the reaction chamber; continuously supplying an inert gas to the reaction chamber; continuously controlling a pressure of the reaction chamber in a range of 15 kPa to 80 kPa; and applying RF power for glow discharge in a pulse to one of the parallel plate electrodes.