Selective PEALD Oxide Deposition via Hydrogen Plasma
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Solution Overview
Problem
The semiconductor industry faces challenges in achieving selective plasma enhanced atomic layer deposition (PEALD) of oxides, particularly in depositing oxides on dielectric surfaces while avoiding metal surfaces, as existing methods often require oxygen plasma, which can lead to non-selective deposition and process complexity.
Innovation Solution
A PEALD process that uses a hydrogen plasma generated in a gas without oxygen to selectively deposit oxides like SiO2, SiOC, or metal oxides on dielectric surfaces by alternately contacting the substrate with a precursor containing silicon or metal and a hydrogen plasma, which reacts with the dielectric surface to form the oxide while inhibiting growth on metal surfaces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If oxygen plasma is used in PEALD process, then oxide deposition can be achieved, but selectivity between dielectric and metal surfaces is lost
Solution Approach 1:
The patent changes the chemical parameters of the plasma reactant from oxygen-based to hydrogen-based, which fundamentally alters the reaction chemistry. Hydrogen plasma reacts selectively with dielectric surfaces to form oxides while being inhibited by metal surfaces, achieving >90% selectivity without requiring complex process control
2Productivity
If selective oxide deposition on dielectric surfaces is achieved, then process steps are reduced, but deposition control and uniformity may be compromised
Solution Approach 1:
The patent employs periodic alternation between precursor exposure and hydrogen plasma exposure in a cyclic PEALD process. This periodic action enables self-limiting surface reactions that deposit uniform films layer-by-layer, achieving both high selectivity and excellent film uniformity control
Solution Approach 2:
Hydrogen plasma acts as an intermediary reactant that mediates the deposition process. It enables oxide formation on dielectric surfaces through hydrogen-assisted oxidation mechanisms while being blocked by metal surfaces, providing both selectivity and controlled deposition
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 allows for selective deposition of oxides with high selectivity (>90%) and control over film thickness and composition, reducing process steps and costs by avoiding oxygen plasma, thus enhancing the efficiency and precision of semiconductor manufacturing.
Implementation Method 1
a second reactant comprising reactive species from a plasma
Implementation Method 2
plasma enhanced atomic layer deposition (PEALD)
Implementation Method 3
The second reactant also reacts with the metal surface to reduce metal oxide that may be present on the metal surface
Implementation Method 4
The second reactant may also remove OH groups that may be present on the metal surface
Data Source
AI summary
Methods for selectively depositing oxide thin films on a dielectric surface of a substrate relative to a metal surface are provided. The methods can include at least one plasma enhanced atomic layer deposition (PEALD) cycle including alternately and sequentially contacting the substrate with a first precursor comprising oxygen and a species to be included in the oxide, such as a metal or silicon, and a second plasma reactant. In some embodiments the second plasma reactant comprises a plasma formed in a reactant gas that does not comprise oxygen. In some embodiments the second plasma reactant comprises plasma generated in a gas comprising hydrogen.