Plasma-Free Etching Using Interhalogen Gases for Semiconductor Fabrication
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Solution Overview
Problem
Current semiconductor device manufacturing processes face challenges in achieving high reliability and electrical characteristics due to plasma damage and limited etch selectivity, which affect the integration and performance of semiconductor devices.
Innovation Solution
A plasma-free etching process using interhalogen compounds like F2 and XeF2, combined with a hydrogen replacement process, is employed to selectively etch semiconductor substrates, minimizing plasma damage and enhancing etch selectivity, thereby improving the fabrication of semiconductor devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If plasma etching process is used, then etching speed is improved, but plasma damage occurs on the substrate
Solution Approach 1:
The patent replaces the plasma-based etching mechanism with a chemical vapor deposition (CVD) based etching mechanism. Specifically, it uses a two-step process: first forming a mask pattern on the substrate, then selectively removing unmasked regions through CVD etching using chemicals such as iron chloride, hydrogen fluoride, or ammonium fluoride. This substitution eliminates plasma damage while achieving controlled etching speeds through chemical reactions.
Solution Approach 2:
The patent changes the fundamental parameters of the etching process by transitioning from plasma physics to chemical reactions. It controls etching through chemical concentration, temperature, and reaction time rather than plasma power and ion flux. This parameter transformation allows precise control of etching speed while avoiding the harmful effects of plasma exposure on the substrate.
2Device complexity
If conventional etching process is used, then manufacturing process is simple, but etch selectivity is limited
Solution Approach 1:
The patent segments the etching process into distinct steps: mask pattern formation, selective chemical etching of unmasked regions, and subsequent processing. This segmentation allows different chemicals to be applied at different stages to achieve high selectivity for different materials (oxide, nitride, metal) while maintaining clear process boundaries that prevent excessive complexity.
Solution Approach 2:
The patent introduces mask patterns as intermediary elements that mediate between the substrate and the chemical etching agents. These masks selectively protect certain regions while exposing others, enabling precise control of etching selectivity. The masks act as intermediaries that translate design requirements into selective material removal without requiring complex direct etching chemistry.
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 results in semiconductor devices with improved reliability and electrical characteristics by reducing plasma damage and increasing etch selectivity, leading to higher manufacturing margins and better device performance.
Implementation Method 1
etching the etching target through a plasma-free etching process that uses an etching gas including one of an interhalogen compound, F2, XeF2, and combinations thereof
Implementation Method 2
performing a hydrogen replacement process on the substrate after the plasma-free etching process is performed, wherein the hydrogen replacement process may include: providing gas with hydrogen on the substrate where the plasma-free etching process has been performed, and performing a thermal treatment process on the substrate
Data Source
AI summary
Provided is a method of fabricating a semiconductor device. The method includes: preparing a substrate with an etching target, and etching the etching target through a plasma-free etching process that uses an etching gas including one of interhalogen compound, F2, XeF2 and combinations thereof.