Metal Boride ALD via Decaborane Pulsing
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Solution Overview
Problem
Current methods for depositing metal borides, such as CVD and PVD, face challenges with high substrate temperatures and non-conformal coverage, especially in semiconductor fabrication, and lack an effective low-temperature ALD solution using decaborane.
Innovation Solution
The method involves pulsing a metal halide precursor and decaborane precursor onto a substrate in an atomic layer deposition process, with repeated cycles and inert gas purging to form metal boride films at low temperatures, using precursors like titanium tetrachloride, niobium pentachloride, and tantalum pentafluoride, achieving conformal coverage and low thermal budgets.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If CVD methods are used to deposit metal borides, then metal film can be deposited, but substrate temperature becomes excessively high (up to 1200°C)
Solution Approach 1:
The patent changes the deposition method from conventional CVD to atomic layer deposition (ALD), which fundamentally alters the reaction parameters and enables metal boride formation at much lower temperatures (below 400°C), thus resolving the contradiction between achieving deposition and maintaining thermal budget compatibility
Solution Approach 2:
The patent replaces the thermal activation mechanism of CVD with a surface-mediated ALD process, where metal halide precursors react with decaborane on the substrate surface at low temperatures, substituting high-temperature thermal fields with a controlled surface reaction mechanism
2Manufacturing precision
If PVD methods are used to deposit metal films, then metal film can be deposited, but conformality coverage becomes insufficient on complex substrate contours
Solution Approach 1:
The patent replaces the line-of-sight geometric constraint of PVD with the surface-mediated chemical reaction mechanism of ALD, where metal halide and decaborane precursors react on the substrate surface to form metal boride, achieving excellent conformality on complex contours without geometric limitations
Solution Approach 2:
The patent changes the deposition mechanism from physical vapor deposition (line-of-sight) to atomic layer deposition (surface-mediated chemical reactions), fundamentally altering how the film forms and enabling uniform coverage on complex geometries
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 the formation of metal boride films with low resistivity and high chemical resistance, suitable for various applications, including n-metal gates, gate fills, and integrated circuits, with controlled growth rates and compositions, while avoiding the limitations of high-temperature processes.
Implementation Method 1
a reaction between the metal halide precursor and the decaborane precursor forms a film comprising at least one of: titanium boride (TiB), tantalum boride (TaB), or niobium boride (NbB)
Implementation Method 2
performing a metal precursor deposition onto the substrate... pulsing a metal precursor onto the substrate
Data Source
AI summary
A method for depositing a metal film onto a substrate is disclosed. In particular, the method comprises pulsing a metal halide precursor onto the substrate and pulsing a decaborane precursor onto the substrate. A reaction between the metal halide precursor and the decaborane precursor forms a metal film, specifically a metal boride.