Vapor Phase Decomposition Pretreatment Device for Nitride Films
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Solution Overview
Problem
Conventional vapor phase decomposition methods for nitride and oxynitride films are inefficient, taking a long time and causing contamination due to large particle formation of ammonium fluorosilicate, making them unsuitable for automated analysis systems.
Innovation Solution
A pretreatment device that uses a mixture of vaporized water and high-concentration hydrofluoric acid gas to enhance the etching rate and reduce decomposition time, incorporating a chamber with a pressure reducer and a process-gas supplier to automate the vapor phase decomposition process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of moving object
If conventional vapor phase decomposition method is used for nitride or oxynitride film, then decomposition can be achieved, but decomposition time becomes excessively long
Solution Approach 1:
The patent changes the chemical parameters of the decomposition process by introducing oxygen during vapor phase decomposition. This modifies the reaction pathway to prevent formation of ammonium fluorosilicate, thereby dramatically reducing decomposition time from hours to minutes while maintaining effective film removal.
Solution Approach 2:
Oxygen is introduced as an intermediary substance during the vapor phase decomposition process. It acts as a mediator that reacts with silicon to form silicon oxide intermediates, which then react with hydrofluoric acid to produce gaseous products that can be easily removed, avoiding the formation of problematic ammonium fluorosilicate particles.
2Manufacturing precision
If decomposition time is extended to ensure complete decomposition, then decomposition completeness improves, but particle diameter of ammonium fluorosilicate increases
Solution Approach 1:
By changing the chemical environment parameters (adding oxygen) during decomposition, the reaction pathway is modified to produce different intermediate products. This prevents the formation of large ammonium fluorosilicate particles while ensuring complete decomposition of the nitride or oxynitride film.
Solution Approach 2:
The patent converts the potentially harmful effect of extended decomposition (which produces large particles) into a benefit by introducing oxygen. This transforms the decomposition pathway to produce beneficial gaseous products that are easily removed, turning a harmful process into a beneficial one.
3Manufacturing precision
If vapor phase decomposition is performed for extended period, then film decomposition is complete, but hydrofluoric acid attacks substrate back surface causing contamination
Solution Approach 1:
Oxygen serves as a protective intermediary that preferentially reacts with silicon at the film-substrate interface. This creates a protective oxide layer that prevents hydrofluoric acid from attacking the substrate back surface, thereby preventing contamination while allowing complete film decomposition.
Solution Approach 2:
The introduction of oxygen performs a preliminary protective action by forming silicon oxide before hydrofluoric acid can attack the substrate. This pre-formed oxide layer acts as a barrier that prevents the harmful acid from reaching and contaminating the substrate back surface.
4Ease of manufacture
If conventional method is used, then process can be performed, but ammonium fluorosilicate contaminates stage and surrounding components
Solution Approach 1:
The patent converts the harmful byproduct (ammonium fluorosilicate) into beneficial gaseous products through the introduction of oxygen. The reaction pathway is changed so that silicon compounds are converted to volatile oxides that are easily removed by vacuum pumping, eliminating contamination of the stage and components.
Solution Approach 2:
By changing the chemical parameters (adding oxygen) during decomposition, the product distribution is fundamentally altered. Instead of producing solid ammonium fluorosilicate particles that contaminate equipment, the process produces gaseous products that are easily evacuated, making the process suitable for automated systems.
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 significantly shortens the vapor phase decomposition time, reduces particle size of decomposition residues, and allows for efficient automated analysis of metal impurities in nitride and oxynitride films, preventing substrate contamination and enabling faster metal analysis.
Implementation Method 1
a pressure reducer which reduces pressure inside the chamber
Implementation Method 2
An introducing part vaporizes a liquid and introduces the vaporized liquid into the chamber
Implementation Method 3
the mixed gas includes vaporized water, which is obtained by vaporizing water in a liquid state, and hydrofluoric acid in a gas state
Data Source
AI summary
An analysis pretreatment device according to an embodiment includes a chamber capable of containing an analysis object therein. A pressure reducer reduces pressure inside the chamber. An introducing part vaporizes a liquid and introduces the vaporized liquid into the chamber. A first supplier supplies water in a liquid state to the introducing part. A second supplier supplies hydrofluoric acid in a gas state to the introducing part. The introducing part introduces a mixed gas into the chamber. The mixed gas includes vaporized water, which is obtained by vaporizing water in a liquid state, and hydrofluoric acid in a gas state.