Capacitor Interfacial Film Structure for Higher Semiconductor Capacitance
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Solution Overview
Problem
As semiconductor devices become more integrated and capacitive, achieving sufficient capacitance for improved refresh characteristics and yield is challenging due to the need for high dielectric films and increased contact areas between electrodes.
Innovation Solution
The semiconductor device incorporates a substrate with a lower electrode, a dielectric film, and upper and lower interfacial films made of conductive single films with a metal element having higher electronegativity than the dielectric film, enhancing capacitance and reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If a dielectric film with high dielectric constant is used to increase capacitance, then capacitance increases and refresh characteristics improve, but manufacturing complexity and material selection difficulty increase
Solution Approach 1:
The capacitor structure is segmented into multiple functional layers: lower electrode, lower interfacial film, dielectric film, upper interfacial film, and upper electrode. Each layer performs a specific function, with the interfacial films specifically engineered to reduce band offsets while the dielectric film provides high capacitance. This segmentation allows optimization of each component independently to achieve overall performance improvement.
Solution Approach 2:
The invention uses composite material structures, particularly for the interfacial films which combine metal elements with specific electronegativity characteristics. The dielectric film uses high-k materials such as hafnium oxide or zirconium oxide combined with metal oxide layers. This composite approach enables simultaneous achievement of high capacitance and reduced band offsets that cannot be obtained with single materials.
2Quantity of substance
If contact area between lower electrode and dielectric film is increased to increase capacitance, then capacitance increases, but manufacturing precision requirements increase
Solution Approach 1:
Instead of merely increasing the lateral contact area between electrode and dielectric film, the invention utilizes the vertical dimension by introducing interfacial films with reduced band offsets. This allows the capacitance to be enhanced through improved vertical electrical coupling and reduced tunneling losses, rather than relying solely on lateral area expansion which would demand tighter process control.
Solution Approach 2:
The invention changes the electrical parameters of the interface by selecting metal elements with specific electronegativity values (greater than 1.5 on the Pauling scale). This parameter change in the interfacial film composition optimizes the band alignment and reduces the effective contact resistance, enabling improved capacitance without proportionally increasing the physical contact area.
3Quantity of substance
If metal elements with higher electronegativity are used in interfacial films to reduce band offsets, then valence and conduction band offsets decrease and capacitance increases, but material selection and manufacturing complexity increase
Solution Approach 1:
The interfacial films act as intermediary layers between the electrode and dielectric film. These films are specifically designed with metal elements of high electronegativity to mediate the band alignment interface. By introducing this intermediary layer with optimized electrical properties, the invention reduces the direct interface defects and tunneling losses, thereby improving capacitance without requiring the electrode or dielectric film themselves to be modified.
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 configuration increases capacitance, improves refresh characteristics, and enhances the overall reliability and yield of semiconductor devices by optimizing the interfacial films' electronegativity and structure.
Implementation Method 1
An electronegativity of the metal element included in each of the first lower interfacial film and the first upper interfacial film is greater than an electronegativity of a metal element included in the dielectric film
Implementation Method 2
reduce valence and conduction band offsets
Implementation Method 3
a dielectric film on the first lower interfacial film, a first upper interfacial film on the dielectric film, and an upper electrode on the first upper interfacial film
Implementation Method 4
enhance the dielectric properties of the capacitor
Data Source
AI summary
Disclosed is a semiconductor device. The semiconductor device includes a lower electrode disposed on a substrate; a first lower interfacial film disposed on the lower electrode; a dielectric film disposed on the first lower interfacial film; a first upper interfacial film disposed on the dielectric film; and an upper electrode disposed on the first upper interfacial film, wherein each of the first lower interfacial film and the first upper interfacial film is a conductive single film, and the first lower interfacial film and the first upper interfacial film include the same metal element, wherein electronegativity of the metal element included in each of the first lower interfacial film and the first upper interfacial film is greater than electronegativity of a metal element included in the dielectric film.