Memory Hole Sidewall Film Reforming to Suppress Bowing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
During the manufacturing of three-dimensional semiconductor memory devices, the shape of holes with high aspect ratios tends to bow due to inadequate sidewall protection, leading to increased processing time and potential etching issues.
Innovation Solution
A method involving the formation of a sidewall film using a first gas containing carbon and fluorine elements, followed by a second process where the sidewall film is reformed using a gas containing hydrogen, specifically H2S, to reduce fluorine concentration and enhance etching resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If a sidewall protection film is formed on the side face of the hole to prevent bowing, then the shape stability is improved, but the etching resistance may be insufficient if the film quality or amount is inadequate
Solution Approach 1:
The patent changes the chemical composition parameters of the sidewall protection film by controlling the ratio of carbon-containing gas to fluorine-containing gas during deposition. This creates a film with optimal carbon and fluorine concentration ratios that simultaneously provides shape stability and sufficient etching resistance for high-aspect-ratio hole processing.
Solution Approach 2:
The patent creates a composite sidewall protection film containing both carbon and fluorine elements with specific concentration ratios. This composite structure combines the benefits of carbon-based films (etching resistance) and fluorine-based films (deposition control), achieving both shape stability and etching resistance.
2Manufacturing precision
If the processing time is increased to improve hole shape control, then the manufacturing precision is improved, but the productivity decreases
Solution Approach 1:
The patent performs preliminary formation of a sidewall protection film with optimized carbon and fluorine composition before the main etching process. This preliminary action creates a protective barrier that prevents hole bowing during etching, allowing the main etching process to proceed faster without compromising shape control, thus improving productivity while maintaining manufacturing precision.
3Ease of manufacture
If the fluorine concentration in the sidewall film is high to improve deposition control, then the film formation is improved, but the etching resistance decreases
Solution Approach 1:
The patent optimizes the concentration ratio of carbon and fluorine elements in the sidewall protection film by adjusting gas flow rates during deposition. By maintaining a specific carbon-to-fluorine ratio where carbon concentration is sufficiently high, the film achieves both good deposition control and enhanced etching resistance, resolving the trade-off between ease of manufacture and reliability.
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
The method effectively suppresses the bowing of memory holes by reducing fluorine concentration in the sidewall film, thereby preventing excessive etching and ensuring the formation of high-aspect-ratio memory holes with improved structural integrity.
Implementation Method 1
performing a second process of exposing the second film to a second gas containing a hydrogen element or a fluid generated from the second gas
Data Source
AI summary
In one embodiment, a method of manufacturing a semiconductor device includes forming a first film on a substrate. The method further includes performing a first process of forming a concave portion in the first film and forming a second film on a surface of the first film that is exposed in the concave portion by using a first gas containing a carbon element and a fluorine element. The method further includes performing a second process of exposing the second film to a second gas containing a hydrogen element or a fluid generated from the second gas.