Microwave Plasma Processing for Ge Oxide Film Interface Quality
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Solution Overview
Problem
Current techniques for forming oxide films on Ge substrates with high-k films result in poor electrical characteristics due to high interface state density and equivalent oxide thickness (EOT), necessitating improved film quality and reduced EOT while maintaining low processing temperatures and high controllability of film thickness.
Innovation Solution
A method involving a plasma processing apparatus that forms a first high-k film on a Ge substrate, followed by a plasma oxidation or nitriding process using microwaves to create a thin oxide film with reduced interface state density, and a second high-k film, optimizing power density, temperature, and processing conditions to achieve desired film thickness and quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a Ge oxide film is formed using slot antenna type plasma processing to improve interface electrical characteristics, then interface state density is reduced, but film thickness controllability and processing temperature control are compromised
Solution Approach 1:
The patent replaces the slot antenna type plasma processing system with a microwave plasma processing system. This substitution enables precise control of plasma power and temperature through microwave parameters, while maintaining the ability to form high-quality Ge oxide films with reduced interface state density. The microwave system provides better controllability of film thickness and processing conditions compared to the slot antenna approach.
Solution Approach 2:
The patent changes the plasma generation parameters by using microwave frequency electromagnetic waves instead of slot antenna configurations. This parameter change allows independent control of plasma power and substrate temperature, enabling formation of thin Ge oxide films (0.3 nm or less) with precise thickness control while maintaining low processing temperatures and high interface quality.
2Reliability
If a thin Ge oxide film of 0.3 nm or less is formed to reduce interface state density, then electrical characteristics are improved, but processing temperature control and film quality are compromised
Solution Approach 1:
The patent replaces conventional plasma processing with microwave plasma processing, which enables independent control of plasma power and substrate temperature. This substitution allows formation of ultra-thin Ge oxide films (0.3 nm or less) with precise temperature control, maintaining low processing temperatures while achieving the desired film thickness and interface quality that were previously compromised.
3Productivity
If the EOT of the gate insulating film is reduced to achieve high mobility, then device performance is improved, but interface quality and film thickness control are compromised
Solution Approach 1:
The patent replaces conventional plasma processing with microwave plasma processing to enable precise control of film formation. This substitution allows reduction of EOT while maintaining excellent film thickness control and interface quality, thereby achieving high device mobility without compromising manufacturing precision. The microwave system provides the necessary control authority to form ultra-thin, high-quality oxide films.
4Temperature
If low-power microwave plasma is used to form oxide film at low temperature, then processing temperature is reduced, but power distribution control and film uniformity are compromised
Solution Approach 1:
The patent segments the microwave power distribution into multiple independent channels, each capable of separate control. This segmentation allows uniform power distribution across the substrate surface even at low total power levels, enabling formation of uniform oxide films at low processing temperatures without compromising film uniformity. The multi-channel architecture provides precise spatial control of plasma generation.
Solution Approach 2:
The microwave processing system is designed to perform multiple functions: it can control both the total power level and the spatial distribution of plasma generation independently. This multi-functionality allows the system to maintain low processing temperatures while simultaneously ensuring uniform film formation across the substrate, resolving the contradiction between temperature reduction and film uniformity.
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 reduces interface state density and EOT, improving electrical characteristics and controllability of the oxide film, suitable for next-generation semiconductor devices.
Implementation Method 1
a plasma processing apparatus that forms a first high-k film on a semiconductor substrate, followed by a plasma oxidation or nitriding process using microwaves
Implementation Method 2
plasma oxidation or nitriding process using microwaves to create a thin oxide film
Implementation Method 3
a microwave output unit configured to generate microwaves and distribute and output the microwaves to a plurality of channels
Implementation Method 4
plasma oxidation or nitriding process using microwaves to create a thin oxide film
Implementation Method 5
plasma oxidation or nitriding process using microwaves
Data Source
AI summary
A method for manufacturing an insulating film laminated structure includes a step of forming a first high-k film on a semiconductor substrate, a step of processing the semiconductor substrate in a processing chamber of a plasma processing apparatus by using a plasma to form an oxide film on an interface between the semiconductor substrate and the first high-k film, and a step of forming a second high-k film on the first high-k film. A plasma oxidation process is performed by using a plasma of an oxygen-containing gas at a processing temperature of the semiconductor substrate in a range from 20° C. to 145° C. while setting a power density of a total power of microwaves to be within a range from 0.035 kW/m2 to 3.5 kW/m2 with respect to a total area of a conductive member facing an inner space of the processing chamber and microwave transmitting windows.