Halogen Gas Etching Sequence for Complete Nitride Film Removal
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing etching methods using gases containing boron and halogen elements result in low etching rates and inadequate film removal.
Innovation Solution
A method involving the simultaneous supply of a first halogen element-containing gas and a second halogen element-containing gas, along with inert gases, to enhance the etching process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a gas containing boron and a halogen element is used for etching, then the etching process can be performed, but the etching rate is low and the film is not sufficiently removed
Solution Approach 1:
The patent combines multiple halogen element-containing gases (first halogen gas and second halogen gas) into a single etching process. The first halogen gas (e.g., BCl3) provides initial etching capability, while the second halogen gas (e.g., Cl2) enhances the etching rate and ensures complete film removal. This merging of multiple gas functions resolves the contradiction by achieving both high productivity (etching rate) and reliability (complete film removal) simultaneously.
2Productivity
If only a gas containing boron and a halogen element is used, then the process is simple, but the etching rate is low
Solution Approach 1:
The patent makes the gas supply system multi-functional by introducing a second halogen gas that serves multiple purposes: enhancing the etching rate, ensuring complete film removal, and working synergistically with the first halogen gas. This multi-functionality approach allows the system to achieve high etching rates while maintaining reasonable complexity, as the second gas complements rather than replaces the first gas's functions.
3Reliability
If a gas containing boron and a halogen element is used without additional gases, then the process configuration is simple, but the film cannot be sufficiently removed
Solution Approach 1:
The patent changes the chemical composition parameters of the etching gas by introducing a second halogen gas with different properties from the first halogen gas. For example, using BCl3 as the first gas and Cl2 as the second gas creates a synergistic effect where the combined gas mixture achieves complete film removal. This parameter change (adding a second gas component) resolves the contradiction between reliability and device complexity by optimizing the chemical parameters rather than adding complex physical structures.
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 efficiently removes films by weakening bonds between elements, thereby improving the etching rate and ensuring complete film removal.
Implementation Method 1
This approach efficiently removes films by weakening bonds between elements
Data Source
AI summary
An etching technique removes a film by supplying a first gas containing a first halogen element and a second gas containing a second halogen element. In embodiments, the first gas includes a Group 13 halide and the second gas includes a chlorine-containing compound with a Group 16 element. The gases are introduced with different start times, optionally with a period of simultaneous supply, so the first gas weakens bonds in a nitride or oxide and the second gas accelerates removal. The method suits cleaning deposits from internal surfaces of a process vessel and etching films on a substrate. After etching, a cyclic purge removes residual species. A pre-coating step may form a nitride film to suppress diffusion of elements and stabilize initial film growth.