FTIR Dopant Profiling for Non-Contact Semiconductor Characterization
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Solution Overview
Problem
Existing semiconductor fabrication processes face challenges in accurately determining dopant profiles without physical contact, particularly in less stringently controlled environments, leading to variations in semiconductor device properties that deviate from desired specifications.
Innovation Solution
A non-contact method using Fourier-transform infrared spectroscopy (FTIR) and infrared reflectometry to measure dopant profiles by correlating reflectance and transmittance intensity across various wavelengths, integrating with semiconductor fabrication processes to identify process disturbances and deviations from desired specifications.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If physical contact methods (probes) are used to measure dopant profiles, then measurement capability is achieved, but manufacturing precision and device consistency deteriorate due to physical disturbance and contact variability
Solution Approach 1:
The patent replaces mechanical contact-based measurement systems with optical-based FTIR spectroscopy. The system uses infrared radiation to probe the semiconductor device, eliminating physical contact between measurement probes and the device. This substitution of mechanical measurement with optical measurement prevents physical disturbance to the device while maintaining measurement capability, thereby improving both measurement precision and manufacturing precision.
2Manufacturing precision
If non-contact FTIR measurement is implemented, then manufacturing precision and device consistency improve, but measurement capability and dopant profile accuracy may deteriorate without proper calibration
Solution Approach 1:
The patent implements preliminary calibration procedures where reference measurements are taken from devices with known dopant profiles before production measurements. The system establishes correlation curves between FTIR spectral parameters and actual dopant concentrations through these preliminary calibration steps. This preliminary action ensures that the non-contact measurement system is properly calibrated, maintaining measurement precision while achieving manufacturing precision benefits.
Solution Approach 2:
The patent introduces an intermediary calibration model that translates FTIR spectral data into dopant profile information. Rather than directly measuring dopant concentrations, the system measures infrared absorption spectra and uses pre-established correlation relationships (intermediaries) to infer dopant profiles. This intermediary approach maintains measurement accuracy while enabling non-contact measurement capabilities.
3Productivity
If traditional process control operations are used, then manufacturing simplicity is maintained, but productivity and real-time monitoring capability deteriorate
Solution Approach 1:
The patent makes the FTIR measurement system universal by designing it to handle multiple measurement functions through a single integrated platform. The system can measure different dopant profiles, perform various calibration operations, and provide real-time monitoring across different device types. This multi-functionality increases productivity while managing device complexity through consolidation rather than proliferation of separate measurement systems.
Solution Approach 2:
The patent implements feedback mechanisms where real-time FTIR measurements are continuously monitored and compared against target specifications. The system provides immediate feedback on dopant profile deviations, enabling real-time process adjustments. This feedback capability dramatically improves productivity and real-time monitoring while the automated nature of the feedback loop manages operational complexity.
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 real-time, non-contact characterization of dopant profiles, improving accuracy and reducing reliance on physical probes, thereby enhancing the consistency and efficiency of semiconductor manufacturing.
Implementation Method 1
The sensed radiation may include radiation originating from the infrared radiation source that has reflected from the semiconductor device
Implementation Method 2
The sensed radiation may include radiation originating from the radiation directing device that has penetrated and emerged from the semiconductor device
Data Source
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AI summary
Systems and methods for non-contact characterization of semiconductor devices. Systems may include: an infrared radiation source directing radiation towards the semiconductor device; a radiation directing device positioned proximal the infrared radiation source to direct radiation towards an opposing side of the semiconductor device, the semiconductor device receivable between the radiation directing device and the infrared radiation source; and a radiation detector proximal to the infrared radiation source to sense radiation associated with a plurality of infrared wavebands from the semiconductor device for determining a dopant profile property of the semiconductor device. The sensed radiation may include radiation originating from the infrared radiation source reflected from the semiconductor device. The sensed radiation may include radiation originating from the radiation directing device and emerging from the semiconductor device. The dopant profile properties may be based on infrared reflectance or infrared transmittance associated with the plurality of respective infrared wavebands.