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Silicon Metal-oxide-semiconductor Quantum Dots for Single-electron Pumping
Published on: June 3, 2015
Silicon doping system at the research reactor FRM II
X Li1, H Gerstenberg, I Neuhaus
1Forschungsneutronenquelle Heinz Maier-Leibnitz (FRM II), Technische Universität München, Lichtenbergstrasse 1, D-85747 Garching, Germany. xiaosong.li@frm2.tum.de
Summary
Silicon doping at FRM II utilizes an automated system for high-resistivity silicon ingots. This system achieves precise doping homogeneity of +/-5% using optimized neutron flux profiles and continuous ingot rotation.
Area of Science:
- Nuclear Engineering
- Materials Science
- Semiconductor Manufacturing
Background:
- Silicon doping is crucial for semiconductor production.
- FRM II reactor has implemented silicon doping capabilities.
- Optimizing neutron flux is essential for uniform doping.
Purpose of the Study:
- To describe the automated silicon doping system at FRM II.
- To detail the methods for achieving precise doping homogeneity.
- To discuss the doping procedure and quality for high-resistivity silicon.
Main Methods:
- Neutron flux profile determination using a test rig.
- Design and optimization of a nickel absorber liner using MCNP-code.
- Implementation of an automated doping system with continuous ingot rotation.
- Online neutron flux density measurement with self-powered neutron (SPN) detectors.
Main Results:
- Successful commissioning of an automated silicon doping system.
- Achievement of target doping homogeneity of +/-5%.
- Capability to irradiate large silicon single crystals (500mm high, up to 200mm diameter).
Conclusions:
- The automated doping system at FRM II effectively produces high-quality, homogeneously doped silicon.
- The optimized neutron flux profile and rotation system are key to achieving precise doping.
- The system is suitable for producing silicon ingots with high target resistivity.
