Nanocrystalline Diamond Films on Oxide-Rich Amorphous Interfaces
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Solution Overview
Problem
The semiconductor industry faces challenges in achieving high-density integrated circuits due to poor diamond nucleation density on silicon substrates, which is exacerbated by cumbersome seeding methods and substrate damage from bias-enhanced nucleation, leading to carbon-rich interfacial layers that hinder the growth of nanocrystalline diamond films on oxygen-containing materials.
Innovation Solution
A method involving exposure to a first plasma from a plasma source comprising CxHy, CO2, H2, N2, and Ar to treat a silicon substrate, followed by incubation with a hydrocarbon gas stream and a second plasma to nucleate diamond particles, and then exposing the substrate to a third plasma to form a nanocrystalline diamond film directly on an oxide-rich amorphous layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If seeding methods or Bias-enhanced nucleation (BEN) are used to improve diamond nucleation density, then nucleation density increases, but substrate damage occurs and process complexity increases
Solution Approach 1:
The patent applies preliminary oxidation to the silicon substrate surface before diamond deposition, creating a native oxide layer that serves as an intermediate interface. This preliminary action modifies the substrate surface properties to enhance diamond nucleation without requiring mechanical seeding or high-power bias-enhanced nucleation that causes substrate damage.
Solution Approach 2:
The patent introduces an oxide-rich amorphous layer as an intermediary between the silicon substrate and the nanocrystalline diamond film. This intermediate layer mediates the interface between silicon and diamond, providing a suitable surface for diamond nucleation while preventing direct contact that would require damaging pre-treatments.
2Quantity of substance
If seeding methods are used to improve diamond nucleation density, then nucleation density increases, but manufacturing process complexity increases
Solution Approach 1:
The patent performs preliminary oxidation of the silicon substrate to create a native oxide layer before diamond deposition. This preliminary action simplifies the overall process by eliminating the need for separate seeding steps, mechanical abrasion, or complex bias-enhanced nucleation procedures while achieving high nucleation density.
Solution Approach 2:
The patent allows the silicon substrate to self-oxidize in the plasma environment during the deposition process, forming the oxide-rich amorphous layer in-situ. This self-service approach eliminates the need for separate oxidation steps or external seeding materials, simplifying the manufacturing process.
3Quantity of substance
If conventional plasma parameters are used for diamond deposition, then film formation occurs, but nucleation density remains poor
Solution Approach 1:
The patent modifies plasma deposition parameters, specifically using a lower power third plasma (≤50 W) after nucleation compared to conventional high-power deposition. This parameter change allows adequate time for high-density nucleation on the oxide-rich surface while still forming quality nanocrystalline diamond films, achieving both high nucleation density and good film quality.
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 method enables high-density, high-hardness nanocrystalline diamond films with low stress and excellent thermal conductivity, suitable for use as hard masks in semiconductor processing, particularly in 3D-NAND structures, without requiring cumbersome seeding or substrate pre-treatments.
Implementation Method 1
exposing a silicon substrate to a first plasma from a first plasma source
Implementation Method 2
The first plasma source comprising one or more of CxHy wherein y≥x, carbon dioxide (CO2), hydrogen (H2), nitrogen (N2), and argon (Ar) to provide a treated substrate
Implementation Method 3
The treated substrate is incubated with a gas stream comprising a hydrocarbon and a second plasma to nucleate diamond particles
Implementation Method 4
Bias-enhanced nucleation (BEN) is one of the few nucleation techniques that can be performed in-situ. It involves the bombardment of methane-rich (4-10%) ionized gas species on the surface of a negatively-charged biased substrate
Implementation Method 5
The seeded substrate is exposed to a third plasma having a power greater than 50 W to form a nanocrystalline diamond film
Implementation Method 6
a method of depositing diamond-like carbon hard mask films on amorphous interfacial layers
Data Source
AI summary
Methods of depositing a nanocrystalline diamond film are described. The method may be used in the manufacture of integrated circuits. Methods include treating a substrate with a plasma to form a treated substrate surface, incubating the treated substrate with a carbon-rich plasma to nucleate diamond particles on the treated substrate surface, followed by treating the substrate with a plasma to form a nanocrystalline diamond film. The resulting nanocrystalline diamond films are formed on an interfacial oxide-rich amorphous layer between the nanocrystalline diamond film and a silicon substrate.