Gate Interface Engineering for High-k Dielectric Leakage Reduction
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Solution Overview
Problem
Conventional technologies face challenges in maximizing the performance of high-k dielectric materials due to morphology issues, leading to increased gate leakage and reduced device yield as effective oxide thickness decreases, limiting the scalability of logic gate structures.
Innovation Solution
The method involves removing native oxide from a substrate surface using nitrous oxide and thermal annealing to form an oxide-containing interface, followed by the deposition of high-k dielectric materials using atomic layer deposition, with pre- and post-treatments involving nitrogen- and oxygen-containing precursors to control grain growth and stabilize the film, thereby enhancing the dielectric constant and reducing gate leakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the thickness of silicon oxide gate dielectric is reduced to improve capacitance and channel mobility, then device performance improves, but gate leakage increases and device yield decreases
Solution Approach 1:
The patent changes the material parameter from silicon oxide to high-k dielectric materials (such as hafnium oxide, zirconium oxide, or their alloys with silicon oxide), which have higher dielectric constants. This allows achieving the required capacitance at greater thickness, thereby maintaining device performance while reducing gate leakage.
Solution Approach 2:
The patent employs composite gate dielectric structures combining high-k materials with silicon oxide layers. The high-k material layer provides high capacitance, while the silicon oxide layer controls interface quality and leakage, creating a composite structure that balances performance and reliability.
2Reliability
If high-k materials are adopted to reduce effective oxide thickness while limiting gate leakage, then device yield improves, but morphology issues limit the maximization of high-k material performance
Solution Approach 1:
The patent applies preliminary surface treatment to the substrate before depositing high-k materials. This includes removing native oxide and performing surface conditioning to create an optimal surface state that promotes uniform nucleation and growth of high-k material, thereby improving morphology.
Solution Approach 2:
The patent optimizes deposition parameters (temperature, pressure, precursor flow rates) and annealing conditions to control the crystalline structure, grain size, and surface morphology of high-k materials, transforming them from amorphous or poorly crystalline states to well-controlled morphologies with enhanced performance.
3Ease of manufacture
If conventional deposition methods are used for high-k materials, then process simplicity is maintained, but morphology issues arise that limit material performance
Solution Approach 1:
The patent introduces intermediary treatment steps (surface preparation, buffer layers, or interfacial engineering) between the substrate and high-k material deposition. These intermediary layers or treatments mediate the interface properties, enabling better adhesion and morphology control without significantly complicating the overall manufacturing process.
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 produces high-k dielectric materials with improved morphology, resulting in higher dielectric constants and reduced gate leakage, enabling thinner effective oxide thickness without compromising device performance, with gate leakage currents significantly lower than those of silicon oxide-based films.
Implementation Method 1
delivering nitrous oxide to the substrate and thermally annealing the surface to form an oxide-containing interface
Implementation Method 2
delivering a nitrogen-containing precursor or an oxygen-containing precursor to a substrate contained in a semiconductor processing chamber. The methods may include introducing reactive ligands on an exposed surface of the substrate with the nitrogen-containing precursor or the oxygen-containing precursor
Implementation Method 3
forming a high-k dielectric material comprises performing an atomic layer deposition process
Implementation Method 4
delivering nitrous oxide to the substrate and thermally annealing the surface to form an oxide-containing interface
Data Source
AI summary
Processing methods may be performed to produce semiconductor structures that may include a high-k dielectric material. The methods may include removing a native oxide from a surface of a substrate. The methods may include delivering nitrous oxide to the substrate and thermally annealing the surface to form an oxide-containing interface. The methods may include delivering a nitrogen-containing precursor or an oxygen-containing precursor to a substrate contained in a semiconductor processing chamber. The methods may include forming reactive ligands on an exposed surface of the substrate with the nitrogen-containing precursor or the oxygen-containing precursor. The methods may also include forming a high-k dielectric material overlying the substrate.