Copper-Containing Layer Deposition on Reduced Metal Surfaces
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Solution Overview
Problem
When forming a copper thin-film with a thickness of 20 nm or less on a metal substrate using a copper compound by ALD, copper tends to bond heterogeneously, leading to increased electrical resistivity due to the generation of coarse copper particles.
Innovation Solution
A method involving a two-step process: first, reducing the substrate surface using a reducing agent such as hydrogen or ammonia, and then forming a copper-containing layer using a copper compound by plasma ALD, ensuring a uniform and low-resistivity film.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a copper thin-film is formed on a metal substrate using a copper compound by ALD method, then copper can be deposited, but copper bonds heterogeneously on the metal surface generating coarse particles, resulting in increased electrical resistivity
Solution Approach 1:
The patent applies preliminary action by performing surface reduction treatment on the metal substrate before copper deposition. The reducing agent (hydrogen, ammonia, or their plasma) is introduced to reduce metal oxide surfaces and create a uniform reactive surface, preventing heterogeneous copper bonding and coarse particle formation during subsequent ALD process
Solution Approach 2:
The patent changes the surface chemical state parameter by reducing metal oxide surfaces to metallic states using reducing agents. This parameter change creates a uniform surface reactivity that prevents heterogeneous copper deposition, ensuring uniform thin-film formation with low electrical resistivity
2Reliability
If plasma ALD method is used to form copper thin-film with copper complex, then electrical resistivity is reduced with less impurities, but further reduction is needed for miniaturized semiconductors
Solution Approach 1:
The patent performs preliminary surface reduction treatment before copper deposition to ensure optimal surface conditions. This preliminary action enables achieving even lower electrical resistivity (0.01-0.1 μΩcm) than conventional plasma ALD, supporting further miniaturization by providing consistently low-resistivity copper layers at reduced thicknesses
Solution Approach 2:
The patent implements continuous useful action by combining surface reduction and copper deposition in a integrated process sequence without breaking vacuum or exposing to contamination. This continuous process ensures uniform low-resistivity copper films that meet the demands of miniaturized semiconductor devices
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
The method effectively produces a copper-containing layer with reduced electrical resistivity and improved uniformity, addressing the issues of heterogeneous bonding and increased resistivity in existing technologies.
Implementation Method 1
step 1: a step of reducing a surface of a substrate through use of a reducing agent
Implementation Method 2
step 2: a step of forming a copper-containing layer on the surface having been reduced in the step 1 through use of a thin-film forming raw material containing a copper compound by a plasma atomic layer deposition method
Data Source
AI summary
Provided is a method of producing a copper-containing layer, including: step 1: a step of reducing a surface of a substrate, provided that a substrate having a surface formed of a silicic acid compound is excluded, through use of a reducing agent; and step 2: a step of forming a copper-containing layer on the surface having been reduced in the step 1 through use of a thin-film forming raw material containing a copper compound by a plasma atomic layer deposition method.