Selective Semiconductor Film Formation on Nitride Using Fluorine Adsorption
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing film forming methods face challenges in selectively forming semiconductor films on nitride films without hindering the formation on adjacent oxide films, due to the interference of chlorine-containing gases with silicon nitride film formation.
Innovation Solution
A film forming method involving the adsorption of fluorine onto a substrate with exposed nitride and oxide regions, creating a stepped surface by selectively etching the nitride film, and subsequently forming a semiconductor film using a semiconductor material gas, while preventing lateral protrusion and ensuring precise thickness control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If chlorine-containing gas is supplied to form silicon nitride film, then silicon nitride film formation is enabled, but film formation on silicon oxide film is hindered
Solution Approach 1:
Fluorine is supplied in advance to adsorb onto the silicon oxide film surface before silicon nitride film formation, creating a protective layer that prevents chlorine-containing gas from reacting with the oxide film, thereby enabling selective film formation on nitride regions only
Solution Approach 2:
Fluorine acts as an intermediary substance that selectively adsorbs onto the silicon oxide film surface, creating a barrier that mediates between the chlorine-containing gas and the oxide film, preventing unwanted reactions while allowing desired film formation on nitride regions
2Manufacturing precision
If semiconductor film is formed on both nitride and oxide films, then complete coverage is achieved, but lateral protrusion and unwanted deposition occur
Solution Approach 1:
A stepped surface is created by selectively etching the nitride film to be more deeply recessed than the oxide film surface before semiconductor film formation, establishing a geometric barrier that prevents lateral protrusion and unwanted deposition on oxide regions
Solution Approach 2:
The substrate surface is given different local geometries through selective etching, creating a stepped structure where the nitride region is recessed and the oxide region remains at a higher level, enabling spatially differentiated film formation control
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 method allows for selective semiconductor film formation on nitride films while avoiding deposition on oxide films, enhancing processing efficiency and precision by controlling the incubation time and etching conditions to achieve the desired film thickness and prevent unwanted granular material deposition.
Implementation Method 1
adsorbing fluorine onto a substrate on which a region in which a nitride film is exposed and a region in which an oxide film is exposed are provided adjacent to each other by supplying a fluorine-containing gas to the substrate
Implementation Method 2
forming a stepped surface on a side surface of the oxide film by selectively etching the nitride film
Implementation Method 3
selectively forming a semiconductor film on the nitride film by supplying a raw material gas including a semiconductor material to the substrate
Data Source
AI summary
There is provided a film forming method including: adsorbing fluorine onto a substrate on which a region in which a nitride film is exposed and a region in which an oxide film is exposed are provided adjacent to each other by supplying a fluorine-containing gas to the substrate, and forming a stepped surface on a side surface of the oxide film by selectively etching the nitride film, among the nitride film and the oxide film, so as to cause a surface of the nitride film to be more deeply recessed than a surface of the oxide film; and after the adsorbing the fluorine onto the substrate and forming the stepped surface, selectively forming a semiconductor film on the nitride film, among the nitride film and the oxide film, by supplying a raw material gas including a semiconductor material to the substrate.