Oxide Film Deposition Using Carbon Inhibitors for Void-Free Gap Fill
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Solution Overview
Problem
Conformal oxide film deposition methods, such as atomic layer deposition (ALD), struggle to fill gaps with high aspect ratios or reentrant features without leaving voids, particularly in applications like 3D NAND memory fabrication and self-aligned double patterning, due to uneven film growth rates.
Innovation Solution
Incorporating a carbon-containing inhibitor during oxide film deposition cycles, which adsorbs nonconformally, preferentially inhibiting film growth closer to the gap opening by consuming oxygen-containing gases, thereby promoting uniform gap filling without voids.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conformal oxide film deposition is used to fill gaps, then uniform film thickness is achieved, but voids form in high aspect ratio gaps and reentrant features
Solution Approach 1:
The patent introduces a carbon-containing inhibitor that selectively adsorbs on specific crystallographic planes of the substrate, creating locally different oxide film growth rates. This local quality variation causes preferential growth in certain directions, enabling nonconformal filling of high aspect ratio gaps and reentrant features while maintaining overall film quality.
2Reliability
If nonconformal oxide film growth is achieved using carbon-containing inhibitor, then gap filling is improved, but film quality may deteriorate
Solution Approach 1:
The patent carefully controls deposition parameters including temperature, pressure, gas flow rates, and inhibitor concentration to optimize the balance between nonconformal growth and film quality. By adjusting these parameters, the process achieves complete gap filling while maintaining film uniformity and avoiding defects.
3Productivity
If oxide film deposition is performed in conventional ALD process, then deposition speed is maintained, but voids are left in gaps with high aspect ratios
Solution Approach 1:
The patent employs periodic deposition cycles alternating between conformal and nonconformal growth steps. The carbon-containing inhibitor is introduced in specific cycles to create nonconformal growth, while other cycles maintain conformal growth. This periodic action allows the process to achieve both high deposition speed and uniform gap filling by leveraging the complementary strengths of both growth modes.
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
Enables controlled nonconformal oxide film growth, effectively filling gaps with high aspect ratios and reentrant structures, reducing void formation and tapering issues in spacers, while maintaining film quality.
Implementation Method 1
a carbon-containing inhibitor, which adsorbs nonconformally, preferentially inhibiting film growth closer to the gap opening
Implementation Method 2
the adsorbed oxide-film precursor is chemically converted into a film on the substrate, for example by oxidation to form an oxide film
Implementation Method 3
reacting the oxide-film precursor and the oxygen-containing gas, and exposing the substrate to a carbon-containing inhibitor
Data Source
AI summary
Examples are disclosed that relate to using a carbon-containing inhibitor to grow an oxide film nonconformally on a substrate. One example comprises performing a plurality of oxide film deposition cycles, at least one oxide film deposition cycle of the plurality of oxide film deposition cycles comprising exposing the substrate to an oxide-film precursor to adsorb oxide-film precursor to the substrate, exposing the substrate to an oxygen-containing gas, reacting the oxide-film precursor and the oxygen-containing gas, and exposing the substrate to a carbon-containing inhibitor.