Substrate Temperature Measurement Using Reflectivity and Emission Signals
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The time resolved reflectivity method for anneal monitoring in semiconductor manufacturing is ineffective in detecting slight variations, leading to degraded process control.
Innovation Solution
A method combining time resolved reflectivity and emission signals for advanced anneal monitoring, utilizing a light emitting source, polarizer, and detector to enhance temperature determination accuracy and precision.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If time resolved reflectivity method is used for anneal monitoring, then the measurement can be performed, but the detection precision is insufficient for slight variations
Solution Approach 1:
The patent combines time-resolved reflectivity signals with emission signals to create a hybrid measurement approach. The reflectivity signal provides information about surface phase changes while the emission signal provides temperature information, and their combination enables detection of slight temperature variations that neither method could detect alone, thereby improving measurement precision and process control reliability
Solution Approach 2:
The patent introduces an intermediary analysis method that processes both reflectivity and emission signals together. This intermediary approach allows the system to extract temperature information from the combined signals, enabling detection of subtle temperature changes during annealing that would be invisible to either method used separately
2Measurement precision
If time resolved reflectivity method is used, then anneal monitoring is performed, but slight variations during the process cannot be detected
Solution Approach 1:
By merging reflectivity and emission signals, the system captures both surface phase change information and thermal radiation information. This combination preserves information about slight temperature variations and process changes that would be lost when using only reflectivity measurement, thereby improving detection precision without losing process variation information
3Measurement precision
If single method (reflectivity) is used for temperature measurement, then the system is simple, but accuracy is degraded
Solution Approach 1:
The patent merges two measurement methods (reflectivity and emission) into a unified temperature measurement system. While this increases device complexity compared to using a single method, the combination enables accurate temperature measurement during annealing processes, particularly for detecting slight temperature variations and phase transitions that single-method systems cannot accurately measure
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
Improves the accuracy and precision of temperature measurement during semiconductor processing by synchronizing reflectivity and emission signals, allowing for precise detection of phase transitions and temperature changes.
Implementation Method 1
a detector, which, in operation, receives reflectivity signals that includes the transverse electric waves of the light signals reflected from a surface of the substrate
Implementation Method 2
a detector, which, in operation, receives emission signals emitted from the surface of the substrate. The emission signals are representative of at least one of a temperature or energy density of the surface of the substrate
Data Source
AI summary
A temperature measuring apparatus for measuring a temperature of a substrate is described. A light emitting source that emits light signals such as laser pulses are applied to the substrate. A detector on the other side of the light emitting source receives the reflected laser pulses. The detector further receives emission signals associated with temperature or energy density that is radiated from the surface of the substrate. The temperature measuring apparatus determines the temperature of the substrate during a thermal process using the received laser pulses and the emission signals. To improve the signal to noise ratio of the reflected laser pulses, a polarizer may be used to polarize the laser pulses to have a S polarization. The angle in which the polarized laser pulses are applied towards the substrate may also be controlled to enhance the signal to noise ratio at the detector's end.