Segmented Electrode Plasma Processing for Vertical Trench Etching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current plasma processing technologies face challenges in achieving fine control over the shape of trenches and via holes in semiconductor manufacturing, often resulting in tapered sidewalls which affect electrical performance.
Innovation Solution
A plasma processing apparatus with a substrate electrode divided into multiple electrode element groups, utilizing high-frequency and low-frequency power sources to generate plasma and apply voltages with different phases, allowing ions to be diagonally incident on the substrate, thereby improving precision and reducing tapering.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional plasma processing is used, then the etching process can be performed, but the sidewall of trench becomes tapered and fine control of processing shape is difficult
Solution Approach 1:
The substrate electrode is divided into multiple electrode element groups (first, second, third, and fourth groups) arranged in different directions. Each group can be independently controlled by separate low-frequency power sources, allowing differential voltage application to precisely control ion incident angles and achieve vertical sidewall profiling.
Solution Approach 2:
Different electrode element groups are assigned different low-frequency voltages with different phases to create localized electric field variations. This enables different regions of the substrate to experience different ion bombardment angles, achieving vertical sidewalls in specific areas while maintaining etching efficiency.
2Manufacturing precision
If multiple low-frequency power sources with different phases are applied to electrode element groups, then ion incident angle can be controlled for vertical sidewall formation, but device complexity increases
Solution Approach 1:
The substrate electrode is segmented into multiple independently controllable electrode element groups, each connected to a separate low-frequency power source. This segmentation enables precise spatial control of ion incident angles through differential phase control, achieving vertical sidewall formation.
Solution Approach 2:
The high-frequency power source serves dual functions: generating plasma and providing baseline substrate bias. The low-frequency power sources are added specifically for sidewall angle control, allowing the system to maintain plasma generation efficiency while adding shape control capability.
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 enables precise control over the etching process, reducing tapering on sidewalls and enhancing the verticality of processed features, leading to improved electrical performance and reduced residue deposition.
Implementation Method 1
The high-frequency power source outputs a high-frequency voltage for ionizing the process gas to generate plasma
Implementation Method 2
The plurality of low-frequency power sources apply a plurality of low-frequency voltages of 20 MHz or less with mutually different phases for introducing ions from the plasma
Data Source
AI summary
In one embodiment, a plasma processing apparatus includes: a chamber; an introducing part; a counter electrode; a high-frequency power source; and a plurality of low-frequency power sources. A substrate electrode is disposed in the chamber, a substrate is directly or indirectly placed on the substrate electrode, and the substrate electrode has a plurality of electrode element groups. The introducing part introduces process gas into the chamber. The high-frequency power source outputs a high-frequency voltage for ionizing the process gas to generate plasma. The plurality of low-frequency power sources apply a plurality of low-frequency voltages of 20 MHz or less with mutually different phases for introducing ions from the plasma, to each of the plurality of electrode element groups.