Plasma-Free Halogen Fluoride Etching for Selective Ti/In/Sn Removal
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Solution Overview
Problem
Existing methods for etching metals like titanium, indium, and tin in semiconductor elements face challenges such as non-selective etching and high energy consumption, particularly in dry etching processes involving halogen fluoride, which can damage apparatuses and result in insufficient etching rates.
Innovation Solution
A dry etching method using a halogen fluoride compound of bromine or iodine and fluorine, without plasma, at controlled temperatures and pressures, selectively etches these metals by generating volatile metal fluorides, while minimizing damage to non-etching objects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If wet etching method is used to etch metal-containing materials, then etching can be performed on difficult-to-etch materials, but non-selective etching occurs causing loss of semiconductor element characteristics
Solution Approach 1:
The invention changes the chemical parameters of the etching process by using specific etching solutions containing complexing agents (such as EDTA, DTPA, or HEDTA) combined with oxidants. This parameter change enables selective etching of metal-containing materials while preserving non-metallic regions, thus achieving both etching capability and selectivity
Solution Approach 2:
The invention introduces complexing agents as intermediary substances that selectively bind to metal ions during the etching process. These intermediaries facilitate the removal of metal-containing materials through chelation, while leaving other materials unaffected, thereby achieving selective etching
2Ease of manufacture
If halogen fluoride is used in dry etching to etch metal deposits, then etching can be performed, but high temperature is required causing heavy load on manufacturing apparatus
Solution Approach 1:
The invention changes the temperature parameter from high temperature (conventional dry etching) to low temperature (below 100°C, preferably -50°C to 50°C) by using a different chemical mechanism involving iodine-based etching agents that do not require thermal activation
Solution Approach 2:
The invention replaces the thermal-mechanical etching mechanism (high temperature dry etching) with a chemical mechanism based on iodine complexation and oxidation reactions that proceed efficiently at low temperatures, thereby eliminating the need for high temperature heating
3Ease of manufacture
If halogen fluoride dry etching is used to remove metal deposits, then etching can be performed, but sufficient etching rate cannot be obtained
Solution Approach 1:
The invention changes the chemical composition parameters by using iodine-based etching agents (such as I2, ICl, IBr, or their combinations with oxidants) instead of conventional halogen fluorides, which enables much higher etching rates through more efficient chemical reactions with metal deposits
Solution Approach 2:
The invention employs strong oxidants (such as H2O2, O3, or NF3) in combination with iodine-based agents to accelerate the oxidation of metal deposits, thereby significantly increasing the etching rate and improving productivity
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 enables efficient and selective etching of titanium, indium, and tin at a sufficient rate, reducing apparatus wear and maintaining semiconductor element integrity, thus lowering costs and preventing characteristic loss.
Implementation Method 1
an etching gas containing a halogen fluoride, the halogen fluoride being a compound of bromine or iodine and fluorine, is brought into contact with a member to be etched having an etching object... to etch the etching object
Implementation Method 2
generating volatile metal fluorides
Data Source
AI summary
A dry etching method which includes a dry etching step in which an etching gas containing a halogen fluoride, which is a compound of bromine or iodine and fluorine, is brought into contact with a member to be etched (12) having an etching object, which is an object to be etched by the etching gas, thereby etching the etching object without using plasma. The etching object contains at least one metal selected from among titanium, indium, and tin. Also disclosed is a production method for manufacturing a semiconductor element using the dry etching method as well as a cleaning method for cleaning an inner surface of a chamber of a semiconductor element manufacturing apparatus using the dry etching method.