Monopole Electrostatic Chuck for Semiconductor Wafer Processing
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Solution Overview
Problem
Current Post Exposure Bake (PEB) processes in semiconductor manufacturing are limited by the buildup of sublimation products and out-gassing materials in the bake chamber, leading to defects such as 'open' or 'short' circuits, especially in sub 32 nm processing, and direct contact methods for generating electric fields can introduce defects due to particle transfer or physical deformation.
Innovation Solution
A novel monopole electrostatic chuck design generates an electric field across a semiconductor wafer without direct contact, using charge-changing electrodes and adjustable voltage profiles to enhance acid mobility and improve wafer processing, while also monitoring material buildup in the exhaust lines to initiate cleaning cycles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If direct contact method with metal plate is used to generate electric field, then acid mobility is enhanced, but particle transfer and physical deformation occur causing higher defect levels
Solution Approach 1:
The patent introduces an intermediary electrostatic chuck system that generates electric fields without direct metal plate contact. The chuck uses electrostatic induction to create the necessary electric field for acid mobility enhancement while avoiding the harmful direct contact between metal plates and resist surfaces, thereby reducing particle transfer and physical deformation defects.
Solution Approach 2:
The patent replaces the mechanical direct contact system (metal plate touching resist) with an electrostatic field-based system. The electrostatic chuck generates the required electric field through electrostatic induction without mechanical contact, substituting the mechanical approach with a field-based approach that avoids contamination and deformation issues.
2Temperature
If PEB process is performed in bake chamber, then thermal treating is achieved, but sublimation products and out-gassing build up causing defects
Solution Approach 1:
The patent extracts the electrostatic field generation function from the traditional bake chamber environment. By using an electrostatic chuck that operates independently of the bake chamber's thermal environment, the system separates the electric field generation from the thermal processing, preventing the buildup of sublimation products and out-gassing that occur in conventional integrated systems.
3Object-generated harmful factors
If cleaning of bake system is performed, then byproducts are removed, but processing time is lost and throughput is reduced
Solution Approach 1:
The electrostatic chuck acts as an intermediary system that prevents byproduct buildup in the first place by operating independently from the bake chamber. This preventive approach eliminates the need for periodic cleaning interruptions, maintaining continuous wafer processing and high throughput while still ensuring chamber cleanliness.
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 reduces defects by minimizing particle transfer and deformation, enhances wafer throughput, and maintains chamber cleanliness, ensuring precise control over the PEB process for advanced semiconductor manufacturing.
Implementation Method 1
A novel monopole electrostatic chuck design generates an electric field across a semiconductor wafer without direct contact, using charge-changing electrodes
Implementation Method 2
an electric field can be used to enhance the mobility of acid (H+) in the direction of the field during the post-exposure bake process
Implementation Method 3
a plurality of heating elements can be embedded in the EBP... one or more of the heating elements embedded in the EBP
Data Source
AI summary
An Electrostatic Post Exposure Bake (EPEB) subsystem comprising an Electrostatic Bake Plate (EBP) configured in a processing chamber in an EPEB subsystem, wherein the EPEB wafer comprises an exposed masking layer having unexposed regions and exposed regions therein and the EPEB wafer is developed using the EBP.