Wafer Surface Preclean and SAM Deposition for Reverse Selective ALD
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Solution Overview
Problem
Current preclean processes in semiconductor chambers do not adequately prepare substrates for selective atomic layer deposition (ALD), leading to inefficiencies in metal contact preparation and subsequent ALD processes.
Innovation Solution
An integrated preclean chamber system that uses a remote plasma source to remove residues and oxides, combined with a gas delivery system for self-assembled monolayer (SAM) formation, and a heating system to control substrate temperature, enabling effective surface modification for reverse selective ALD.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a substrate is moved from preclean chamber to ALD chamber for barrier layer deposition, then the substrate can undergo selective ALD deposition, but the substrate is not adequately prepared for selective type ALD depositions
Solution Approach 1:
The patent combines precleaning and SAM deposition functions into a single integrated chamber. The chamber can perform precleaning using plasma or chemical methods, then immediately perform SAM deposition without requiring substrate removal and re-introduction to another chamber. This merging eliminates the gap between precleaning and ALD preparation, ensuring adequate substrate preparation while maintaining continuous processing and high throughput.
2Reliability
If preclean process is performed to remove native oxide on metal contacts, then contact resistance is lowered and adhesion is promoted, but the substrate requires additional preparation steps before ALD
Solution Approach 1:
The patent performs SAM deposition immediately after precleaning while the substrate is still in the chamber and the surface is freshly cleaned. This preliminary action of forming the self-assembled monolayer right after oxide removal ensures the metal surface is properly prepared for selective ALD deposition, eliminating the need for additional preparation steps and reducing overall process complexity.
3Manufacturing precision
If multiple process steps are performed in separate chambers, then each process can be optimized independently, but substrate handling time and contamination risk increase
Solution Approach 1:
The integrated chamber combines precleaning and SAM deposition capabilities in one system. The chamber can be configured with different gas delivery systems and processing zones to perform precleaning operations, then immediately transition to SAM deposition without substrate removal. This merging eliminates substrate handling time and contamination risk between chambers while maintaining the ability to optimize each process step independently through controlled gas flow and parameter adjustment.
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
Enhances the preparation of substrates for ALD, improving contact resistance and adhesion, and reducing costs by integrating precleaning and SAM deposition in a single chamber, thereby increasing throughput and reducing resistive-capacitive (RC) delay.
Implementation Method 1
a remote plasma source (RPS) fluidly coupled to the process chamber and configured to produce radicals or ionized gas mixture with radicals that flow into the processing volume to remove residue or oxides from a surface of the substrate
Implementation Method 2
use radicals (generated by remote plasma) to reduce metal with chemical reaction from the substrate
Implementation Method 3
a heating system located in the pedestal and configured to heat a substrate by flowing gas on a backside of the substrate
Implementation Method 4
the heating system is configured to heat the substrate from approximately 60 degrees Celsius to approximately 450 Celsius to reduce oxide on the surface of the substrate
Implementation Method 5
a first gas delivery system configured to provide at least one first chemical into the processing volume to produce a self-assembled monolayer (SAM) on the surface of the substrate
Implementation Method 6
forming a blocking layer with a first chemical from a first ampoule fluidly connected to the process chamber on at least a portion of the surface of the substrate
Data Source
AI summary
Methods and apparatus for processing a substrate include cleaning and self-assembly monolayer (SAM) formation for subsequent reverse selective atomic layer deposition. An apparatus may include a process chamber with a processing volume and a substrate support including a pedestal, a remote plasma source fluidly coupled to the process chamber and configured to produce radicals or ionized gas mixture with radicals that flow into the processing volume to remove residue or oxides from a surface of the substrate, a first gas delivery system with a first ampoule configured to provide at least one first chemical into the processing volume to produce a SAM on the surface of the substrate, a heating system located in the pedestal and configured to heat a substrate by flowing gas on a backside of the substrate, and a vacuum system fluidly coupled to the process chamber and configured to control heating of the substrate.