Lift Pin With Soft Coating For Semiconductor Substrate Protection
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Solution Overview
Problem
Current lift pins used in semiconductor manufacturing cause scratches and particle release due to their hardness, affecting the quality of semiconductor manufacturing processes.
Innovation Solution
The lift pins are equipped with a contact surface coated with a material layer of lower hardness, such as glassy carbon, and can be hollow with a reduced wall thickness for improved thermal management, along with recessed portions to minimize contact area and prevent damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If lift pins are made of hard material to ensure structural strength, then the mechanical strength of the lift pin is improved, but the substrate surface is damaged causing scratches and particle release
Solution Approach 1:
The lift pin is designed with different material properties at different locations: the shaft is made of hard material (silicon carbide) for structural strength, while the contact surface is covered with a soft material layer (glassy carbon) to prevent substrate damage. This local differentiation of material properties resolves the contradiction between needing hardness for strength and softness for substrate protection.
Solution Approach 2:
The lift pin combines two different materials: silicon carbide for the structural shaft and glassy carbon for the contact surface layer. This composite structure allows the lift pin to simultaneously possess the mechanical strength needed for lifting operations and the surface softness needed to prevent substrate scratching and particle generation.
2Reliability
If lift pins have thick walls for structural integrity, then the mechanical reliability is improved, but the thermal management is worsened causing temperature gradients on the substrate
Solution Approach 1:
The lift pin uses a hollow structure with thin walls (50-1000 μm thickness) instead of solid thick walls. This thin-walled hollow structure reduces thermal mass and improves heat dissipation, preventing temperature gradients on the substrate while maintaining sufficient mechanical reliability through the hollow structural design.
3Stability of the object's composition
If the contact area between lift pin and substrate is large for stable support, then the mechanical stability is improved, but the risk of scratches and particle release increases
Solution Approach 1:
The contact surface is specifically designed with a soft glassy carbon material layer that has different properties from the hard shaft. This local softness at the contact interface prevents scratching and particle generation while the overall lift pin structure maintains mechanical stability through its hollow design and proper dimensions.
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 solution prevents scratches and particle release, ensuring uniform substrate temperature and improved gas seal, thus enhancing the quality and consistency of semiconductor manufacturing processes.
Implementation Method 1
the material layer consists of a glassy carbon layer. This type of material has a hardness which is so low that the material will not damage the substrate surface or the substrate material
Implementation Method 2
The use of a hollow lift pin has an advantageous effect on the thermal management within the reactor chamber, resulting in a reduced thermal mass and heat flow to and from the susceptor and the substrate during the semiconductor process steps
Implementation Method 3
A reduced heat flow between the substrate and the lift pin leads to a more uniform substrate temperature, thus eliminating or reducing the occurrence of quality differences in the substrate (surface) caused by local temperature differences near the lift pins
Data Source
AI summary
The invention relates to a deposition device for comprising a processing space with a substrate support disposed therein, as well as several lift pins (50), which can be moved into and out of the plane of the substrate support to assist in introducing a semiconductor substrate into the processing space and removing it therefrom. The device is characterized in that the contact surface (52) of the lift pin (50) that is to be brought into contact with the semiconductor substrate and/or the substrate support is provided with a material layer (54) which has a lower hardness than the semiconductor substrate and/or the substrate support. This eliminates the risk of damage being caused to the substrate and/or to the substrate support as a result of said substrate shifting undesirably upon being lifted from and lowered onto the substrate support (susceptor). Thus there is no risk of scratches being formed and of particles being released, which might adversely affect the semiconductor manufacturing process.