Guard Wafer Electrostatic Chuck Segmentation
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Solution Overview
Problem
The existing thin film deposition processes in semiconductor fabrication face issues due to the formation of a thick metal layer on the electrostatic chuck, which prevents the device wafer from making direct contact, leading to inaccurate fabrication steps.
Innovation Solution
A guard wafer is placed in direct physical contact with the electrostatic chuck and coated with a thick particle restraining layer, allowing the device wafer to be tightly coupled by preventing the particle restraining layer from forming on the chuck's surface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a thick metal layer is deposited on all surfaces inside the process chamber to absorb and restrain particles, then particle contamination is reduced, but the electrostatic chuck surface becomes covered preventing direct contact with the device wafer
Solution Approach 1:
The electrostatic chuck surface is segmented into two functional zones: a particle-restraining surface area covered by the thick metal layer, and a contact area free of the metal layer where direct wafer coupling occurs. This segmentation allows the chuck to simultaneously perform particle absorption and precise wafer contact functions.
Solution Approach 2:
The electrostatic chuck exhibits local quality differentiation where different surface areas have different properties: most surfaces are covered with the thick metal particle-restraining layer, while a specific contact area remains exposed to enable direct physical contact with the device wafer for accurate positioning and coupling.
2Object-affected harmful factors
If the electrostatic chuck surface is covered with a thick metal layer for particle restraint, then particle absorption is improved, but direct physical contact between the device wafer and chuck is prevented
Solution Approach 1:
The electrostatic chuck surface is divided into functional segments: a particle-restraining area covered by the thick metal layer and a contact area free of metal coating. This segmentation enables the chuck to simultaneously provide particle absorption and reliable direct contact for wafer coupling.
Solution Approach 2:
The electrostatic chuck is designed with non-uniform surface properties where most areas are covered with particle-absorbing metal layer while a specific local area maintains direct access to the chuck surface for reliable wafer contact and coupling.
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 ensures accurate and secure coupling of the device wafer to the electrostatic chuck, enhancing the precision and reliability of the thin film deposition process.
Implementation Method 1
the device wafer is placed on and held in place by an electrostatic chuck in the process chamber
Implementation Method 2
The purpose of this thick metal layer is to absorb and restrain particles residing on the surfaces inside the process chamber
Implementation Method 3
a particle restraining layer is formed on essentially all surfaces that are exposed to the ambient inside the process chamber
Data Source
AI summary
An apparatus (and method for operating the same) which allows tightly coupling the device wafer to the electrostatic chuck of the process chamber after the process chamber is conditioned. The method comprises (a) providing (i) a process chamber and (ii) an electrostatic chuck in the process chamber; (b) placing a guard wafer on the electrostatic chuck via a top surface of the electrostatic chuck; and (c) forming a particle restraining layer on essentially all surfaces that are exposed to the ambient inside the process chamber, wherein the particle restraining layer has a thickness in a first direction of at least 500 Å, wherein the first direction is essentially perpendicular to an interfacing surface between the particle restraining layer and an inner surface of the process chamber, and wherein the guard wafer comprises a material selected from the group consisting of a metal and a semiconductor oxide.