Plasma Processing Apparatus Ring Susceptor Wear Protection
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Solution Overview
Problem
In plasma processing apparatuses, the gap between the semiconductor wafer and the susceptor leads to wear and damage of the sample table's side surface, resulting in foreign objects and reduced manufacturing yield and shorter component life.
Innovation Solution
A plasma processing apparatus design featuring a ring-shaped member with a protruded portion and a dielectric ring-shaped susceptor that seals the space between the wafer and the sample table, preventing plasma from entering and reducing wear, and incorporating a DC power supply for electrostatic suction and a radio-frequency bias power supply for shaping the wafer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a gap is formed between the wafer and the susceptor to protect the sample table, then the sample table is protected from direct plasma exposure, but ions or radicals flow through the gap and cause wear to the side surface portion of the sample table
Solution Approach 1:
A ring-shaped member made of wear-resistant material is introduced as an intermediary component between the sample table and the plasma environment. This ring member has a vertical portion that contacts the wafer outer circumferential portion and a horizontal portion that covers the side surface portion of the sample table, serving as a mediator that protects the sample table from ion and radical attack while allowing the gap structure to remain for plasma access.
Solution Approach 2:
The ring-shaped member is constructed from materials with high wear resistance and plasma resistance properties, such as ceramics or semiconductor materials, which are composite or specialized materials designed to withstand the harsh plasma environment. This allows the structure to resist both mechanical wear from particle bombardment and chemical erosion from reactive radicals.
2Object-generated harmful factors
If the sample table size is reduced to fit within the wafer area, then foreign object generation is reduced, but temperature distribution in the wafer surface during plasma processing is degraded
Solution Approach 1:
The protective structure is extended from a two-dimensional planar configuration to a three-dimensional structure with vertical and horizontal portions. The ring-shaped member rises vertically from the sample table surface and extends horizontally to cover the side surface, creating a protective barrier in multiple spatial dimensions without reducing the sample table area.
3Duration of action of stationary object
If a ring-shaped susceptor is provided to protect the sample table side surface, then wear is reduced, but the size of the sample table decreases
Solution Approach 1:
The protective structure is segmented into distinct functional portions: a vertical portion that contacts the wafer and provides structural support, and a horizontal portion that specifically covers the side surface portion of the sample table. This segmentation allows each portion to be optimized for its specific function while maintaining the overall sample table area.
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 design effectively suppresses foreign object generation, improves manufacturing yield, and prolongs the life of the sample table by reducing wear and maintaining uniform temperature distribution during plasma processing.
Implementation Method 1
a processing chamber in which a sample is processed by using plasma
Implementation Method 2
a first DC power supply which is electrically connected to the sample table and which causes the sample table to generate a suction force
Implementation Method 3
a radio-frequency power supply that supplies radio-frequency power for generating the plasma
Data Source
AI summary
A plasma processing apparatus includes a processing chamber in which a wafer 1 is processed by using plasma, a radio-frequency power supply that supplies radio-frequency power for generating the plasma, a sample table 2 which is arranged in the processing chamber and in which the wafer 1 is mounted, and a DC power supply 106 which is electrically connected to the sample table 2 and which causes the sample table 2 to generate a suction force. The sample table 2 includes a protruded portion 201a that sucks the wafer 1 by the suction force and a level different portion 201b protruding from a lower portion of the protruded portion 201a. A ring 5 that can be in contact with a lower surface of the wafer 1 is provided outside the protruded portion 201a. A space portion 7 formed by the wafer 1, the protruded portion 201a, and the ring 5 is sealed in a state in which the wafer 1 is sucked to an upper surface of the protruded portion 201a of the sample table 2.