Focus Ring Height Control for Uniform Plasma Etching
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Solution Overview
Problem
Existing substrate treating apparatuses face challenges in accurately determining the etching degree of focus rings, leading to inconsistent plasma concentration and potential process defects due to improper replacement timing.
Innovation Solution
A support unit with a temperature sensor and controller to measure and adjust the height of a focus ring based on etching amount, ensuring real-time determination and adjustment of the focus ring's position to maintain uniform plasma distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the focus ring is repeatedly used for etching substrates, then productivity increases, but the focus ring form changes due to etching, causing plasma concentration to deteriorate and manufacturing precision to worsen
Solution Approach 1:
The focus ring is designed with a lifting/lowering mechanism that allows its height to be dynamically adjusted during the etching process. Based on the measured etching amount of the focus ring, the controller automatically changes the height to compensate for form changes, thereby maintaining plasma concentration uniformity throughout extended use periods
Solution Approach 2:
The system changes the height parameter of the focus ring based on measured etching amounts. By monitoring temperature changes that correlate with etching degree and adjusting the height parameter accordingly, the system maintains optimal plasma concentration without requiring frequent ring replacement
2Manufacturing precision
If the focus ring is replaced frequently to maintain plasma concentration, then manufacturing precision is improved, but productivity decreases due to replacement time and device complexity increases
Solution Approach 1:
The system incorporates temperature sensors that continuously monitor the focus ring temperature, which correlates with etching amount. The controller uses this feedback to calculate etching degree and automatically adjusts the focus ring height, creating a closed-loop control system that maintains precision without frequent replacements
Solution Approach 2:
The focus ring system performs self-adjustment through the automated height control mechanism. Based on temperature-based etching measurements, the system automatically compensates for wear, eliminating the need for manual inspection and replacement decisions
3Ease of manufacture
If light irradiation is used to measure focus ring etching degree, then measurement is simplified, but measurement precision is insufficient because only partial area etching can be measured
Solution Approach 1:
The system uses temperature as an intermediary parameter to measure etching degree. Temperature sensors contact the focus ring and measure temperature changes that correlate with etching amount, providing a proxy measurement that reflects total etching across the entire ring without requiring direct visual inspection of the etched surface
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
Accurate etching degree calculation and real-time height adjustment of the focus ring enhance plasma uniformity, extending the focus ring's replacement period and improving substrate treatment efficiency.
Implementation Method 1
a temperature sensor measuring a temperature of the top ring
Implementation Method 2
a plasma source generating a plasma from the process gas
Implementation Method 3
an electrostatic chuck fixing the substrate by an electrostatic force
Data Source
AI summary
The inventive concept provides a substrate treating apparatus. The substrate treating apparatus includes a housing having a treating space treating a substrate; a support unit supporting the substrate at the treating space; a gas supply unit supplying a process gas into the treating space; and a plasma source generating a plasma from the process gas, and wherein the support unit comprises: a dielectric plate placing the substrate on a top surface thereof; a top ring surrounding a circumference of a substrate placed on the dielectric plate; a temperature sensor measuring a temperature of the top ring; a first lifting/lowering member lifting/lowering the top ring; and a controller, and wherein the controller controls the first lifting/lowering member to change a height of the top ring according to an etching amount of the top ring calculated based on the temperature of the top ring measured by the temperature sensor.