Etching Method Using Assistance Layer for Silicon Recesses
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
As the scale of micronization in pattern formation by plasma etching decreases, the deposit formed from plasma gas on the opening or inner wall of a recess can block the opening, preventing the inside from being etched effectively.
Innovation Solution
A method involving the formation of an etching assistance layer on silicon-containing regions, with controlled energy application to remove the layer selectively, allowing for precise etching without forming a protective deposit on the opening, enabling etching even at reduced opening widths.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If plasma gas is used to etch silicon-containing regions, then etching capability is improved, but deposit formation blocks the opening and prevents effective etching inside
Solution Approach 1:
The method applies preliminary action by forming an etching assistance layer on the silicon-containing regions before the actual etching process. This layer is specifically designed to be removed at controlled energy levels, preventing deposit blockage while enabling effective etching inside the recesses. The preliminary formation of this assistance layer allows subsequent etching to proceed without the harmful deposit accumulation that would otherwise block the openings.
Solution Approach 2:
The etching assistance layer serves as an intermediary between the plasma gas and the silicon-containing regions. It mediates the etching process by being selectively removed at specific energy thresholds, allowing plasma to access and etch the interior of recesses without forming blocking deposits on the opening. This intermediary layer enables the plasma to perform its etching function effectively while preventing the harmful side effect of deposit blockage.
2Manufacturing precision
If opening width is reduced for micronization, then pattern precision is improved, but deposit formation completely blocks the opening
Solution Approach 1:
For micronized patterns with reduced opening widths, the preliminary formation of the etching assistance layer becomes even more critical. This layer is formed before etching and is designed to be removed at controlled energy levels, preventing complete blockage of the narrow openings. The preliminary assistance layer ensures that even as opening widths are reduced for higher precision, the openings remain accessible to etching plasma throughout the process.
Solution Approach 2:
The method employs parameter changes by controlling the energy levels applied during processing. The etching assistance layer is designed to be removed at specific energy thresholds that are lower than those required to sputter the underlying silicon-containing regions. By carefully controlling energy parameters, the assistance layer is selectively removed to prevent blockage of micronized openings while preserving the integrity of the pattern precision achieved through reduced opening widths.
3Productivity
If energy is increased to remove etching assistance layer, then layer removal efficiency is improved, but sputtering of underlying region occurs
Solution Approach 1:
The invention utilizes parameter changes by establishing specific energy thresholds for the etching assistance layer. The layer is designed with material composition and thickness parameters that enable its removal at energy levels below those required to sputter the underlying silicon-containing regions. This parameter optimization allows high layer removal efficiency while maintaining selective etching precision, as the energy threshold for assistance layer removal is deliberately set lower than the sputtering threshold of the substrate.
Solution Approach 2:
The etching assistance layer exhibits local quality by having different removal characteristics compared to the underlying silicon-containing regions. The assistance layer is composed of materials with specific binding energies and structural properties that make it removable at lower energy levels. This local quality difference ensures that when energy is applied to remove the assistance layer, only the assistance layer is affected while the underlying regions remain intact, achieving both high removal efficiency and precise selectivity.
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-containing regions, effectively forming recesses during micronization, ensuring the inside of the opening can be etched without blockage, enhancing the precision and effectiveness of the etching process.
Implementation Method 1
forming an etching assistance layer on a surface of at least one of the plurality of silicon-containing regions by plasma of a processing gas
Implementation Method 2
forming an etching assistance layer on a surface of at least one of the plurality of silicon-containing regions by plasma of a processing gas generated in the processing container
Implementation Method 3
imparting energy to the etching assistance layer. The energy is equal to or greater than energy at which the etching assistance layer is removed
Data Source
AI summary
The present disclosure relates to an etching method including: a first step of forming an etching assistance layer on a surface of at least one of a plurality of silicon-containing regions by plasma of a processing gas generated in a processing container; and a second step of imparting energy to the etching assistance layer. The energy is equal to or greater than energy at which the etching assistance layer is removed, and smaller than energy at which a region located immediately below the etching assistance layer is sputtered, and a sequence including the first step and the second step is executed repeatedly.