Exhaust Growth Monitor Layout for In-Situ EPI Thickness Control
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Solution Overview
Problem
Current semiconductor processing systems lack precise in situ monitoring of film growth thickness, leading to imprecise deposition rates and increased downtime due to the use of conventional sensors that do not provide accurate film growth determination, thereby affecting throughput and production yields.
Innovation Solution
The implementation of parametric resonance sensors within an exhaust system in a semiconductor process chamber, combined with a configuration of fins and baffles, to measure film thickness and adjust process parameters for improved growth rate control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional sensors are installed within the process chamber to monitor film growth, then measurement capability is provided, but measurement precision is insufficient and device complexity increases
Solution Approach 1:
A parametric resonance sensor is installed in the exhaust system rather than directly in the process chamber. The sensor measures film growth on a monitor substrate in the exhaust path, which serves as an intermediary to infer the film growth rate on the actual semiconductor substrate. This approach provides accurate measurement capability while avoiding the complexity and contamination risks of installing sensors directly in the process chamber.
Solution Approach 2:
The patent replaces conventional mechanical or contact-based thickness measurement methods with a parametric resonance sensing system. The sensor detects changes in resonance frequency of a cantilever beam coated with deposited material, providing precise measurement without mechanical contact or direct chamber intervention.
2Productivity
If sensors are added to the process chamber for real-time monitoring, then productivity is improved through better control, but loss of time increases due to calibration and measurement downtime
Solution Approach 1:
The measurement function is extracted from the process chamber environment and placed in the exhaust system. The parametric resonance sensor monitors film growth on a monitor substrate in the exhaust path, allowing real-time measurement without opening or interrupting the process chamber operation. This eliminates calibration and measurement downtime while maintaining productivity benefits.
Solution Approach 2:
The parametric resonance sensor provides continuous real-time monitoring of film growth rates during the entire deposition process. The measurement is performed continuously on the monitor substrate in the exhaust system, enabling ongoing process control without interruption to substrate processing, thereby eliminating downtime associated with periodic measurements.
3Loss of information
If process chamber conditions are monitored between calibration and measurement operations, then measurement data is obtained, but manufacturing precision decreases due to chamber condition changes
Solution Approach 1:
The monitor substrate in the exhaust system serves as an intermediary that experiences the same deposition conditions as the process chamber but allows for continuous measurement. The parametric resonance sensor provides real-time feedback on deposition rate without requiring the chamber to be opened or conditions to change between calibration and measurement, maintaining manufacturing precision.
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
Enables precise, real-time monitoring of film growth rates with increased sensitivity and sensor life, reducing downtime and improving film thickness uniformity across the substrate.
Implementation Method 1
At least one growth monitor is a parametric resonance sensor
Data Source
AI summary
A method and apparatus for processing semiconductor substrates is described herein. The apparatus includes one or more growth monitors disposed within an exhaust system of a deposition chamber. The growth monitors are parameteric resonance monitors and are configured to measure the film thickness grown on the growth monitors while a substrate is being processed within the deposition chamber. The growth monitors are connected to a controller, which adjusts the heating apparatus and gas flow apparatus settings during the processing operations. Measurements from the growth monitors as well as other sensors within the deposition chamber are used to adjust processing chamber models of the deposition chamber as substrates are processed therein.