Electrostatic Chuck Charge Removal Using Fluctuating Plasma Power
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Solution Overview
Problem
Existing substrate treatment processes face challenges in effectively removing residual charges from substrates after processing, which can prevent proper substrate separation and potentially cause damage during handling.
Innovation Solution
A substrate treating apparatus and method that utilizes a power supplying unit to generate a fluctuating pattern of DC and RF power to the plasma generating unit, allowing for a discharging plasma to increase the disorder degree of residual charges on the substrate, thereby reducing electrostatic forces and facilitating safe substrate handling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a charge of the substrate is discharged using plasma, then the substrate can be separated from the electrostatic chuck, but residual charges remain on the substrate causing handling difficulties
Solution Approach 1:
The patent applies periodic action by using a power supplying unit that supplies power in a fluctuating pattern with multiple stages. The discharge process is divided into sequential phases: initial discharge phase, intermediate phase with adjusted power levels, and final discharge phase. This multi-stage periodic power supply effectively removes residual charges that single-phase discharge cannot eliminate, thereby improving substrate handling ease without compromising separation reliability.
2Force
If DC voltage is applied to the substrate supporting unit, then the substrate is fixed by electrostatic force, but residual charges remain after processing
Solution Approach 1:
The patent extracts the harmful residual charges from the substrate by introducing a dedicated discharge plasma generation step. The power supplying unit supplies fluctuating power to generate discharge plasma specifically for charge removal. This extraction process separates the fixed charge function (during processing) from the charge removal function (after processing), effectively eliminating residual charges that cause handling problems while maintaining the necessary electrostatic force during the actual processing.
3Productivity
If plasma is generated for discharge, then charges are removed from the substrate, but the discharge process is incomplete with remaining charges
Solution Approach 1:
The patent applies dynamics by making the power supply fluctuating rather than static. The power supplying unit dynamically adjusts power levels through a fluctuating pattern with multiple stages, changing power intensity according to the discharge progress. This dynamic power adjustment ensures complete charge removal by adapting the discharge conditions, preventing the incompleteness that occurs with constant power supply while maintaining high discharge efficiency.
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
The apparatus effectively discharges residual charges on the substrate, ensuring safe handling and preventing damage by increasing the disorder degree of the charges, thus improving the substrate handling process.
Implementation Method 1
The substrate in the process chamber can be supported by an electrostatic chuck. The electrostatic chuck can fix the substrate with electrostatic force generated by electrostatic induction.
Implementation Method 2
a plasma generating unit for generating a discharging plasma for discharging a charge of the substrate
Data Source
AI summary
Provided is an apparatus for treating a substrate. The substrate treating apparatus includes a substrate supporting unit for supporting the substrate and fixing the substrate with electrostatic force, a plasma generating unit for generating a discharging plasma for discharging a charge of the substrate, and a power supplying unit for supplying power to the substrate supporting unit and the plasma generating unit, wherein the power supplying unit supplies power of a fluctuating pattern to the plasma generating unit when a charge of the substrate is discharged.