Wafer Laser Annealing Power Control for Reflectivity Variation
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Solution Overview
Problem
As semiconductor devices are fabricated with increasingly smaller features, variations in reflectivity across different areas of a wafer lead to non-uniform temperature distribution during laser annealing, affecting the quality and integration of electronic components.
Innovation Solution
A wafer annealing system that measures the reflectivity of different areas on a semiconductor wafer and adjusts the power of laser shots to achieve uniform temperature across the wafer by using a controller to determine and adjust the power and duration of laser shots based on reflectivity measurements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If laser annealing is performed on a semiconductor wafer, then the crystalline structure is restored and film properties are enhanced, but non-uniform temperature distribution occurs due to variations in reflectivity across different areas of the wafer
Solution Approach 1:
The system applies different laser powers to different areas of the wafer based on their local reflectivity characteristics. The controller adjusts the laser power for each shot according to the measured reflectivity of the target area, ensuring that each region receives the appropriate energy to reach the desired temperature uniformly.
Solution Approach 2:
The system measures the reflectivity of each area on the wafer before laser annealing and uses this measurement as feedback to adjust the laser power. The controller determines the laser power based on the reflectivity measurement, creating a closed-loop control system that compensates for reflectivity variations and achieves uniform temperature distribution.
2Productivity
If the minimum feature size is reduced to improve integration density, then more components can be integrated into a given area, but additional problems arise in the fabrication processes and techniques
Solution Approach 1:
The system changes the laser power parameter dynamically based on the reflectivity measurement of each area. By adjusting the laser power to compensate for reflectivity variations, the system maintains process quality and reduces defects even as feature sizes are reduced and integration density increases.
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 system ensures that all areas of the wafer reach a desired final anneal temperature range, improving the uniformity and quality of semiconductor devices by restoring crystalline structure and enhancing film properties.
Implementation Method 1
performing a first laser shot on the first anneal region, wherein a power of the first laser shot is set in accordance with the first reflectivity; measuring a first temperature of the first anneal region; and performing a second laser shot on a second anneal region, wherein a power of the second laser shot is set in accordance with the second reflectivity
Implementation Method 2
measuring a first temperature of the first anneal region; measuring a second temperature of the second anneal region
Implementation Method 3
determining a first reflectivity of a first anneal region on a wafer; determining a second reflectivity of a second anneal region on the wafer
Data Source
AI summary
A method of manufacturing a semiconductor device includes: determining a first reflectivity of a first anneal region on a wafer; determining a second reflectivity of a second anneal region on the wafer, performing a first laser shot on the first anneal region, measuring a first temperature of the first anneal region, and performing a second laser shot on a second anneal region. A power of the first laser shot is set in accordance with the first reflectivity. A power of the second laser shot is set in accordance with the second reflectivity.