Low-Temperature Graphene Formation for Semiconductor-Compatible Deposition
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Solution Overview
Problem
Traditional graphene CVD growth requires high temperatures, damaging metal lines and low k films, and existing precleaning methods harm underlying substrate layers.
Innovation Solution
A method involving exposure to argon-hydrogen plasma for cleaning, followed by microwave plasma with hydrocarbon and hydrogen radicals to form graphene at low temperatures, with controlled cooling, and a processing tool with integrated chambers for efficient graphene deposition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If traditional CVD growth with metal catalysts is used to form graphene, then high quality graphene films can be deposited, but high growth temperature (800-1000°C or more) damages metal lines and low k films on device wafers
Solution Approach 1:
The patent changes the temperature parameter from traditional high temperature (800-1000°C) to low temperature (room temperature to 200°C) CVD growth. This parameter change allows graphene formation while avoiding thermal damage to temperature-sensitive components like metal lines and low k films on semiconductor wafers
Solution Approach 2:
The patent introduces copper foil as an intermediary catalyst substrate. The copper foil serves as a temporary carrier for graphene growth, allowing low-temperature CVD to form high-quality graphene that can later be transferred to the target wafer. This intermediary approach enables both high-quality graphene formation and protection of sensitive device structures
2Manufacturing precision
If hydrogen plasma precleaning is used to reduce metal oxides and control nucleation sites, then graphene nucleation is improved, but other films (e.g., low-κ layer) on the substrate are damaged
Solution Approach 1:
The patent changes the temperature parameter during CVD growth to low temperature (room temperature to 200°C), which eliminates the need for aggressive hydrogen plasma precleaning. At these low temperatures, graphene can nucleate and grow directly on the substrate without requiring extensive oxide removal, thereby protecting temperature-sensitive films like low-κ layers
Solution Approach 2:
The patent performs mild surface preparation through argon plasma treatment or chemical etching before CVD growth, creating adequate nucleation sites without the need for aggressive hydrogen plasma cleaning. This preliminary action suffices for low-temperature growth and avoids damage to underlying films
3Quantity of substance
If high temperature CVD is used for graphene growth, then graphene can be formed, but the process is incompatible with current integration flows because metal lines and low k films cannot tolerate such high temperatures
Solution Approach 1:
The patent fundamentally changes the temperature parameter from high (800-1000°C) to low (room temperature to 200°C), making the CVD process compatible with existing semiconductor manufacturing integration flows. This parameter change allows graphene formation without requiring special high-temperature equipment or process interruptions
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
Forms high-quality graphene without damaging underlying layers, compatible with semiconductor manufacturing processes, and reduces thermal stress on substrates.
Implementation Method 1
exposing a substrate comprising one or more of a conductive material and a dielectric material to a first plasma to clean the conductive material, the first plasma formed from an argon-hydrogen containing gas
Implementation Method 2
exposing the substrate to a second plasma to form a graphene layer on the substrate, the second plasma comprising argon, hydrocarbon, and hydrogen radicals
Implementation Method 3
Currently, chemical vapor deposition (CVD) with metal catalysts is used to grow graphene films
Data Source
AI summary
A method of forming graphene layers is disclosed. The method includes precleaning the substrate with a plasma formed from an argon- and hydrogen-containing gas, followed by forming a graphene layer by exposing the substrate to a microwave plasma to form a graphene layer on the substrate. The microwave plasma comprises hydrocarbon and hydrogen radicals. The substrate is then cooled. A capping layer may also be formed.