NiOx Electrode for High-k MIM Capacitor Stability
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Solution Overview
Problem
Existing high dielectric constant (k) metal-insulator-metal (MIM) electronic devices face issues with oxide-stable, high work function electrodes that deteriorate during processing, leading to loss of work function and conductivity due to reactions with hydrogen or oxygen-containing environments.
Innovation Solution
The use of NiOx (nickel oxide) with 1<x≤1.5 as an electrode material in MIM devices, in contact with high k dielectric materials, to form stable and conductive structures, including MIM capacitors, where NiOx is deposited using vapor deposition processes in oxidizing environments to maintain high work function and conductivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If oxide-stable, high work function electrode materials (such as RuO2 or MoO2) are used, then high work function and conductivity are achieved, but the electrode deteriorates during processing due to reactions with hydrogen or oxygen-containing environments
Solution Approach 1:
The invention changes the oxidation state parameter of nickel oxide by controlling the deposition process to achieve NiOx with 1 < x ≤ 1.5. This specific oxidation state range provides the optimal balance between work function (>5.0 eV), conductivity, and stability against further oxidation during subsequent processing steps
Solution Approach 2:
The invention uses nickel oxide as a composite material system where the specific composition NiOx (1 < x ≤ 1.5) combines the high work function characteristics of metal oxides with sufficient electrical conductivity, creating a material that resists further oxidation while maintaining electrical properties
2Reliability
If RuO2 is used as electrode material, then high work function is achieved, but the surface is roughened and material is lost in O3-containing environments
Solution Approach 1:
The invention applies preliminary anti-action by depositing NiOx in a controlled oxidizing environment during the deposition process itself, creating a pre-oxidized, stable surface that is resistant to further oxidation and material loss when exposed to O3-containing environments during subsequent processing
3Reliability
If MoO2 is used as electrode material, then high work function is achieved, but oxygen vacancies occur in the dielectric when contact with high k oxides
Solution Approach 1:
The invention converts the potential harm of oxidation into a benefit by deliberately depositing NiOx in a controlled oxidizing environment to achieve the desired oxidation state (1 < x ≤ 1.5). This pre-oxidized state prevents further oxygen extraction from the dielectric during subsequent processing, eliminating the oxygen vacancy problem while maintaining high work function
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
NiOx provides a stable, high work function electrode material that maintains conductivity and prevents deterioration, enabling the formation of high k dielectric constant metal-insulator structures and MIM capacitors with improved performance and reliability.
Implementation Method 1
NiOx is deposited using vapor deposition processes in oxidizing environments
Implementation Method 2
deposited using vapor deposition processes in oxidizing environments
Data Source
AI summary
A high dielectric constant metal-insulator structure, including an electrode comprising NiOx wherein 1<x≤1.5, and a high k dielectric material in contact with the electrode. The structure may have a further electrode in contact with the high k dielectric material, to form a metal-insulator-metal (MIM) capacitor, e.g., including a bottom electrode comprising NiOx wherein 1<x≤1.5, a high k dielectric material overlying the bottom electrode, and a top electrode comprising NiOx wherein 1<x≤1.5. The NiOx electrodes in such applications are oxide-stable, high work function electrodes that avoid deterioration of work function and conductivity during electronic device fabrication involving elevated temperature annealing.