Plasma Processing Corner Angle Design
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Solution Overview
Problem
In plasma processing apparatuses, deposits accumulate at recessed corners due to reduced ion implantation, leading to wafer defects as the ion sputtering efficiency is lower at these areas, causing uneven plasma processing.
Innovation Solution
Designing a constituent part with recessed corners having an intersection angle of 115 degrees to 180 degrees exposed to plasma, and grooves with a width twice the length of the sheath, to reduce sheath bending and ion diffusion, thereby enhancing ion implantation and preventing deposit accumulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a protrusion or groove with a right angle corner is provided at the upper electrode to control plasma distribution, then plasma uniformity is improved, but deposits accumulate at the corner due to reduced ion implantation
Solution Approach 1:
The invention changes the geometric parameter of the corner angle from a right angle (90 degrees) to an obtuse angle (115-180 degrees). This parameter modification alters the sheath formation and ion implantation characteristics, preventing deposit accumulation while preserving plasma uniformity control capabilities.
Solution Approach 2:
The invention replaces the sharp right angle corner with an obtuse angle corner, which creates a more gradual geometric transition. This curvature modification reduces sheath bending and ion diffusion, allowing ions to implant more effectively at the corner region without accumulating deposits.
2Object-generated harmful factors
If ions are implanted toward the surface to remove deposits through sputtering, then deposit removal is improved, but ion implantation is reduced at recessed corners due to sheath bending
Solution Approach 1:
By changing the corner angle parameter to an obtuse angle (115-180 degrees), the invention modifies the sheath structure and ion trajectory. This ensures that ions can reach the corner region with sufficient flux to maintain effective sputtering and prevent deposit accumulation.
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 configuration reduces the deposition of unwanted material at corners, ensuring uniform plasma processing and preventing wafer defects by maintaining effective ion sputtering and deposit removal.
Implementation Method 1
a sheath 71 is generated along a surface 70 of a constituent part exposed to the plasma in the accommodation chamber, and ions 72 in the plasma are implanted toward the surface of the constituent part by the sheath 71
Implementation Method 2
The implanted ions 72 sputter the deposits deposited on the surface of the constituent part to remove the deposits from the surface of the constituent part
Implementation Method 3
The plasma processing apparatus generates a plasma from a processing gas introduced into the accommodation chamber and performs a desired plasma process on the wafer by using the plasma
Data Source
AI summary
A constituent part is included in a plasma processing apparatus for performing a plasma process on a substrate mounted on a susceptor by using a plasma generated in a processing chamber. The constituent part has at least one recessed corner formed by intersection of two surfaces. The recessed corner is exposed to the plasma when the plasma is generated in the processing chamber. An intersection angle of the two surfaces seen from a plasma side is 115 degrees to 180 degrees.