Semiconductor Metal Removal via Interhalogen Fluoride Volatilization
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Solution Overview
Problem
Existing methods for metal removal in semiconductor element production, such as sputtering and wet etching, risk etching unintended parts of the semiconductor, leading to characteristic loss and are costly due to the use of plasma in dry etching methods.
Innovation Solution
A metal removal method involving the use of a fluoride-containing interhalogen compound to generate metal fluoride, which is then heated in a reduced pressure environment to volatilize and remove the metal-containing material, eliminating the need for plasma excitation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If sputtering method or wet etching method is used to etch metal thin film, then metal removal is achieved, but unintended semiconductor parts are also etched resulting in characteristic loss
Solution Approach 1:
The invention changes the chemical parameters of the etching process by using fluorine-containing interhalogen compounds (such as BrF5, IF7, ClF3) instead of conventional plasma or wet etchants. These compounds react selectively with metal elements (Fe, Co, Ni, Se, Mo, Rh, Pd, W, Re, Ir, Pt) to form volatile metal fluorides that can be removed without affecting semiconductor materials, thereby achieving precise metal removal while preserving semiconductor characteristics.
Solution Approach 2:
The invention employs an inert gas atmosphere (such as nitrogen or rare gases) during the etching process to prevent unwanted reactions with oxygen or moisture. This inert environment ensures that only the intended metal- fluoride reaction occurs, avoiding damage to semiconductor parts and maintaining manufacturing precision while protecting semiconductor element characteristics.
2Productivity
If plasma excited etching gas is used for dry etching of metal thin film, then metal removal efficiency is improved, but cost increases significantly
Solution Approach 1:
The invention extracts the essential function of plasma excitation by directly introducing fluorine-containing interhalogen compounds in their reactive molecular form. This eliminates the need for expensive plasma generation equipment and energy consumption while maintaining high metal removal efficiency, as these compounds naturally react with metals to form volatile fluorides that can be removed through simple heating.
Solution Approach 2:
The invention uses consumable fluorine-containing interhalogen compounds (BrF5, IF7, ClF3) that are introduced in controlled amounts and consumed during the etching process. These chemical reagents provide efficient metal removal without requiring expensive plasma sustainment infrastructure, reducing manufacturing costs while maintaining productivity through direct chemical reaction mechanisms.
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 efficient and cost-effective metal removal and dry etching of semiconductor elements, reducing the risk of etching unintended semiconductor parts and avoiding high plasma-related costs.
Implementation Method 1
bringing a treatment gas containing a fluorine-containing interhalogen compound and a metal-containing material containing a metal element into contact with each other to generate metal fluoride which is a reaction product
Implementation Method 2
heating the metal fluoride under an inert gas atmosphere or in a vacuum environment for volatilization
Implementation Method 3
heating the metal fluoride under an inert gas atmosphere or in a vacuum environment for volatilization
Data Source
Figure 1~2
AI summary
There is provided a metal removal method which can be implemented at a low cost. The metal removal method includes : a reaction step of bringing a treatment gas containing a fluorine-containing interhalogen compound and a metal-containing material containing a metal element into contact with each other to generate metal fluoride which is a reaction product of the fluorine-containing interhalogen compound and the metal element; and a volatilization step of heating the metal fluoride under an inert gas atmosphere or in a vacuum environment for volatilization. The metal element is at least one kind selected from the group consisting of iron, cobalt, nickel, selenium, molybdenum, rhodium, palladium, tungsten, rhenium, iridium, and platinum.