Point defect engineering in germanium
Thesis: Ph. D., Massachusetts Institute of Technology, Department of Materials Science and Engineering, 2016.
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| Format: | Thesis |
| Language: | eng |
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Massachusetts Institute of Technology
2017
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| Online Access: | http://hdl.handle.net/1721.1/108207 |
| _version_ | 1826210313307947008 |
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| author | Monmeyran, Corentin |
| author2 | Lionel C. Kimerling and Anuradha M. Agarwal. |
| author_facet | Lionel C. Kimerling and Anuradha M. Agarwal. Monmeyran, Corentin |
| author_sort | Monmeyran, Corentin |
| collection | MIT |
| description | Thesis: Ph. D., Massachusetts Institute of Technology, Department of Materials Science and Engineering, 2016. |
| first_indexed | 2024-09-23T14:47:50Z |
| format | Thesis |
| id | mit-1721.1/108207 |
| institution | Massachusetts Institute of Technology |
| language | eng |
| last_indexed | 2024-09-23T14:47:50Z |
| publishDate | 2017 |
| publisher | Massachusetts Institute of Technology |
| record_format | dspace |
| spelling | mit-1721.1/1082072019-04-11T05:53:01Z Point defect engineering in germanium Point defect engineering in Ge Monmeyran, Corentin Lionel C. Kimerling and Anuradha M. Agarwal. Massachusetts Institute of Technology. Department of Materials Science and Engineering. Massachusetts Institute of Technology. Department of Materials Science and Engineering. Materials Science and Engineering. Thesis: Ph. D., Massachusetts Institute of Technology, Department of Materials Science and Engineering, 2016. This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections. Cataloged from student-submitted PDF version of thesis. Includes bibliographical references (pages 121-127). In 1947, the first transistor was made of germanium, but soon silicon became the core material of computer chips because of its processability. However, as the typical dimensions of transistors are getting closer to the atomic size, the traditional approach of scaling down transistors to improve performance is reaching its limits, and other elements need to be used in conjunction with silicon. Germanium is one of the key materials to empower silicon based devices because it possesses electronic and optoelectronic properties complementary to those of silicon, among them higher carrier mobilities and a direct band gap (G-valley) at 1.55 [mu]m (the telecom C-band, therefore adding new capabilities to silicon integrated microphotonics). Furthermore, good quality Ge layers can be grown epitaxially on a Si substrate, allowing a monolithic integration of devices. However, compared to silicon, little is known about the point defects in germanium. The goal of the present doctoral work is to remedy this gap. To this end, we have used radiation (gamma rays, alpha particles, and neutrons) to controllably introduce point defects in crystalline germanium, which were then characterized by Deep-Level Transient Spectroscopy (DLTS), a technique that allows the determination of the activation energy, capture cross-section, and concentration of the said defects. By studying their electronic properties, annealing kinetics, and introduction rates, we were able to separate vacancy-containing from interstitial-containing defects and gain insight on their physical nature and formation process. We especially identified a di-interstitial defect and a tri-interstitial defect. In addition, we proved that in the case of alpha particles and neutron irradiation, the fact that defects are generated in a collision cascade influences their carrier capture rates and annealing behaviors. We have also characterized the impact of radiation on commercial germanium-on-silicon photodetectors, and showed that point defects associate with dislocations in epitaxial Ge-on-Si layers. Finally, we have investigated the passivation of midgap states by implanting germanium with fluorine, and showed how the interaction between the halogen element, the amorphous/crystalline interface during the solid phase epitaxy, and the implantation damage is key in obtaining a high performance material by Corentin Monmeyran. Ph. D. 2017-04-18T16:15:06Z 2017-04-18T16:15:06Z 2016 2016 Thesis http://hdl.handle.net/1721.1/108207 980872375 eng MIT theses are protected by copyright. They may be viewed, downloaded, or printed from this source but further reproduction or distribution in any format is prohibited without written permission. http://dspace.mit.edu/handle/1721.1/7582 127 pages application/pdf Massachusetts Institute of Technology |
| spellingShingle | Materials Science and Engineering. Monmeyran, Corentin Point defect engineering in germanium |
| title | Point defect engineering in germanium |
| title_full | Point defect engineering in germanium |
| title_fullStr | Point defect engineering in germanium |
| title_full_unstemmed | Point defect engineering in germanium |
| title_short | Point defect engineering in germanium |
| title_sort | point defect engineering in germanium |
| topic | Materials Science and Engineering. |
| url | http://hdl.handle.net/1721.1/108207 |
| work_keys_str_mv | AT monmeyrancorentin pointdefectengineeringingermanium AT monmeyrancorentin pointdefectengineeringinge |