Middle Electrode Etching Control for Metallic Hard Masks
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Solution Overview
Problem
The increasing complexity of semiconductor devices has made it difficult to process substrates with high aspect ratio patterns using metallic hard masks, as they are prone to etching damage.
Innovation Solution
A substrate processing apparatus with a vacuum chamber, a middle electrode that physically contacts the wafer, and an electric field forming unit comprising upper and lower electrodes, which applies controlled voltages to reduce etching damage by adjusting the electric field and physical energy on the metallic hardmask.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a metallic hard mask is used to form high aspect ratio patterns, then etching selectivity is improved, but etching damage to the hard mask increases
Solution Approach 1:
A middle electrode is introduced as an intermediary component between the upper and lower electrodes. This middle electrode physically contacts the wafer at its end portion and applies a specific potential to the metallic hard mask, acting as a mediator that controls the electric field distribution and reduces direct plasma damage to the hard mask while maintaining etching selectivity
Solution Approach 2:
The patent applies different potentials to three electrodes (upper, middle, and lower) to dynamically control the electric field parameters during etching. By adjusting the potential of the middle electrode that contacts the hard mask, the system optimizes the electric field distribution to reduce ion bombardment energy on the hard mask while maintaining sufficient selectivity
2Device complexity
If conventional two-electrode configuration is used, then device complexity is low, but control precision over electric field is insufficient
Solution Approach 1:
The conventional two-electrode system is segmented into three separate electrodes: an upper electrode, a middle electrode, and a lower electrode. This segmentation allows independent control of electric fields in different regions, enabling precise control over the potential distribution and electric field intensity at the wafer surface and hard mask
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 allows for stable etching processes, reducing damage to the metallic hardmask and enabling the formation of high aspect ratio patterns, improving the precision and reliability of substrate processing.
Implementation Method 1
an electric field forming unit forming an electric field inside the vacuum chamber. The electric field forming unit may include an upper electrode disposed at an upper portion of the inside of the vacuum chamber, a lower electrode disposed in the substrate supporting unit, and a middle electrode disposed between the upper electrode and the lower electrode
Implementation Method 2
supplying one of a reactive gas, a precursor, or a plasma into the vacuum chamber using a gas supplying unit
Data Source
AI summary
A substrate processing apparatus may include a vacuum chamber, a substrate supporting unit disposed at lower portion of an inside of the vacuum chamber, and an electric field forming unit forming an electric field inside the vacuum chamber. The electric field forming unit may include an upper electrode disposed at an upper portion of the inside of the vacuum chamber, a lower electrode disposed in the substrate supporting unit, and a middle electrode disposed between the upper electrode and the lower electrode.