Silicon-Doped ZrO2 Capacitor Dielectric for Leakage Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current semiconductor technologies face challenges in achieving high permittivity and low leakage in capacitor dielectrics, particularly in DRAM devices, as pure ZrO2 exhibits high leakage and Al2O3-based systems reduce effective permittivity, limiting miniaturization and charge storage capacity.
Innovation Solution
A silicon-doped ZrO2 layer with a Si/(Zr+Si) content ranging between 4-9% by atomic ratio is used as the capacitor dielectric, eliminating Al2O3 and incorporating a crystalline ZrSiOx structure with a stoichiometry of Zr(0.96 to 0.91)Si(0.04 to 0.09)O2, along with an interfacial TiO2/TiON layer, to maintain low leakage and high capacitance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If HfO2 is used as capacitor dielectric to increase dielectric constant, then capacitance is improved, but leakage current increases
Solution Approach 1:
The patent changes the compositional parameters of the dielectric by doping ZrO2 with silicon at controlled concentrations (4-9% Si/(Zr+Si) atomic ratio). This parameter modification allows achieving high permittivity similar to HfO2 while maintaining low leakage current, thus resolving the contradiction between capacitance improvement and leakage current reduction
Solution Approach 2:
The patent creates a composite material system by combining ZrO2 with silicon dopants to form silicon-doped ZrO2. This composite approach enables the dielectric to simultaneously exhibit high permittivity for increased capacitance and low leakage current, overcoming the limitations of pure HfO2
2Object-generated harmful factors
If capacitor dielectric film is formed thicker to reduce leakage current, then leakage current is reduced, but capacitance decreases
Solution Approach 1:
By changing the material composition parameters (silicon doping in ZrO2), the patent achieves low leakage current with thinner film thickness. The optimized Si/(Zr+Si) ratio of 4-9% enables maintaining low leakage while increasing capacitance through reduced thickness, directly resolving this contradiction
3Object-generated harmful factors
If discrete Al2O3 layer is added to reduce leakage current in ZrO2-Al2O3 system, then leakage current is reduced, but effective permittivity decreases
Solution Approach 1:
The patent extracts and eliminates the Al2O3 component from the dielectric stack, using pure silicon-doped ZrO2 instead. This removal of the low-permittivity Al2O3 layer prevents the reduction in effective permittivity while still achieving low leakage current through silicon doping, resolving the contradiction between leakage reduction and permittivity maintenance
Solution Approach 2:
The patent changes the compositional parameters by doping ZrO2 with silicon at optimized concentrations, replacing the need for Al2O3 layers. This parameter modification achieves low leakage current without compromising effective permittivity, as the silicon-doped ZrO2 maintains high permittivity throughout the entire film thickness
4Quantity of substance
If ZrO2 layer is scaled thinner to achieve higher capacitance, then capacitance is improved, but crystallization becomes difficult without leakage degradation
Solution Approach 1:
The patent changes the compositional parameters by incorporating silicon dopants in optimized amounts (4-9% Si/(Zr+Si) atomic ratio). This composition modification enables thinner ZrO2 layers to maintain crystalline structure and low leakage performance, allowing capacitance improvement through thickness reduction without sacrificing reliability
Solution Approach 2:
The patent applies local quality modification by doping specific regions of the ZrO2 lattice with silicon atoms. This localized compositional change enhances the material properties, enabling thin films to resist crystallization-induced leakage while maintaining the desired crystalline phase for high permittivity
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 approach allows for higher total capacitance with reduced leakage, enabling continued scaling of DRAM architecture and increased chip density without the need for aggressive thermal treatments, as it stabilizes the crystalline dielectric and improves adhesion and interface quality.
Implementation Method 1
the capacitor dielectric may comprise a silicon-doped ZrO2 layer or crystalline ZrSiOx
Implementation Method 2
A silicon-doped ZrO2 layer with a Si/(Zr+Si) content ranging between 4-9% by atomic ratio
Data Source
AI summary
A capacitor structure includes a storage node; a capacitor dielectric on the storage node; and a plate electrode on the capacitor dielectric. The capacitor dielectric may include a Si-doped ZrO2 layer or crystalline ZrSiOx with a Si/(Zr+Si) content ranging between 4-9% by atomic ratio. The capacitor structure further includes an interfacial TiO2/TiON layer between the storage node and the capacitor dielectric.