Plasma-Free Fluorine Etching of Silicon Compounds With High Selectivity
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Solution Overview
Problem
Existing etching methods for silicon compounds like silicon oxide and silicon nitride require high temperatures and significant energy, leading to non-selective etching of both targets.
Innovation Solution
An etching method using an etching gas containing fluorine gas, applied in the absence of plasma, to selectively etch silicon compounds containing nitrogen or oxygen atoms at temperatures between 40°C and 350°C, while minimizing etching of non-target materials like tantalum, cobalt, and amorphous carbon.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If high temperature (350°C or higher) is used for etching silicon compounds, then etching capability is improved, but energy consumption increases and non-selective etching of non-target materials occurs
Solution Approach 1:
The invention changes the temperature parameter from conventional high temperature (350°C or higher) to a lower temperature range (40°C to less than 350°C). This parameter change enables selective etching of silicon compounds while preventing etching of non-target materials like tantalum, cobalt, copper, titanium nitride, nickel, and amorphous carbon, thereby reducing energy consumption and improving etching selectivity.
2Productivity
If high temperature is used for etching, then etching rate is improved, but selectivity between etching target and non-etching target deteriorates
Solution Approach 1:
The invention optimizes the temperature parameter within a specific range (40°C to less than 350°C) to achieve both adequate etching rate and high selectivity. This parameter optimization allows the etching process to proceed at a practical rate while maintaining the ability to selectively etch only the intended silicon compound targets.
Solution Approach 2:
The invention introduces an intermediary substance (etching gas containing fluorine) that mediates the etching process. The fluorine-containing etching gas selectively reacts with silicon compounds at the optimized temperature range, enabling differentiation between etching targets and non-etching targets, thereby achieving both productivity and precision.
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 the selective etching of silicon compounds without plasma, reducing energy consumption and preventing unwanted etching of non-target materials, thus enhancing the precision and efficiency of semiconductor manufacturing processes.
Implementation Method 1
an etching gas containing fluorine gas is brought into contact with a member to be etched including an etching target being a target of etching with the etching gas... to selectively etch the etching target
Data Source
AI summary
Provided is an etching method capable of selectively etching an etching target containing a silicon compound including at least one of a nitrogen atom or an oxygen atom and a silicon atom with respect to a specific non-etching target without using plasma. The etching method includes an etching step in which an etching gas containing fluorine gas is brought into contact with a member to be etched including an etching target and a non-etching target in the absence of plasma to selectively etch the etching target with respect to the non-etching target. The etching target contains a silicon compound including at least one of a nitrogen atom or an oxygen atom and a silicon atom. The non-etching target includes at least one selected from tantalum, cobalt, copper, titanium nitride, nickel, and amorphous carbon. The etching step is performed under temperature conditions of from 40° C. to less than 350° C.