III-V compositionally graded buffers for heterostructure integration
Thesis: Ph. D. in Electronic, Photonic, and Magnetic Materials, Massachusetts Institute of Technology, Department of Materials Science and Engineering, 2015.
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| Format: | Thesis |
| Language: | eng |
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Massachusetts Institute of Technology
2015
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| Online Access: | http://hdl.handle.net/1721.1/98164 |
| _version_ | 1811071785559392256 |
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| author | Jandl, Adam Christopher |
| author2 | Eugene A. Fitzgerald. |
| author_facet | Eugene A. Fitzgerald. Jandl, Adam Christopher |
| author_sort | Jandl, Adam Christopher |
| collection | MIT |
| description | Thesis: Ph. D. in Electronic, Photonic, and Magnetic Materials, Massachusetts Institute of Technology, Department of Materials Science and Engineering, 2015. |
| first_indexed | 2024-09-23T08:56:10Z |
| format | Thesis |
| id | mit-1721.1/98164 |
| institution | Massachusetts Institute of Technology |
| language | eng |
| last_indexed | 2024-09-23T08:56:10Z |
| publishDate | 2015 |
| publisher | Massachusetts Institute of Technology |
| record_format | dspace |
| spelling | mit-1721.1/981642019-04-10T19:50:19Z III-V compositionally graded buffers for heterostructure integration Jandl, Adam Christopher Eugene A. Fitzgerald. 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. in Electronic, Photonic, and Magnetic Materials, Massachusetts Institute of Technology, Department of Materials Science and Engineering, 2015. Cataloged from PDF version of thesis. Includes bibliographical references (pages 120-125). InyGa₁-yAs alloys are critical in commercial applications such as high speed transistors, light emitting diodes, solid state lasers, photovoltaics, and photo-detectors. However, the range of compositions used in these applications is often limited to the range of InyGa₁-yAs compositions which are lattice matched to elementary or binary semiconductor substrates. Additionally, the integration of InyGa₁-yAs based devices on silicon substrates has been limited by complicated processing procedures. In order to resolve these issues we developed two compositionally graded buffer systems to integrate InyGa₁-yAs devices on InP and Si substrates. The development of InyGa₁-yAs devices on Si substrates also used the direct growth of Ge on Si offcut substrates. InAsxP₁-x compositionally graded buffers were investigated for the growth of InyGa₁-yAs compositions with lattice constants greater than InP. We report the effects of strain gradient, growth temperature, and strain initiation sequence (gradual or abrupt strain introduction) on threading dislocation density, surface roughness, epi-layer relaxation, and tilt. We find that gradual introduction of strain causes increased dislocation densities (>10⁶ cm-²) and tilt of the epi-layer (> 0.10°). A method of abrupt strain initiation is proposed which can result in dislocation densities as low as 1.0x10⁵ cm-² for films graded from the InP lattice constant to InAs₀.₁₅P₀.₈₅. A model for a two-energy level dislocation nucleation system is proposed based on our results. We demonstrate a method for the growth of InyGa₁-yAs devices on Si substrates in a single process run. Two epitaxial layers were used to change the lattice constant from the Si substrate to the InyGa₁-yAs lattice constant. The first layer was a Ge layer grown directly on Si. To reduce the threading dislocation density to < 10⁸ cm-² we investigated the most efficient thermal cycle annealing procedure. The second layer was an InvAl₁-v,As compositionally graded buffer. In₀.₃Ga₀.₇As quantum well devices grown on InvAl₁-v,As/Ge/Si virtual substrates had threading dislocation density of 2x 10' cm-², mobility of 6400 cm2/Vs, and sheet carrier concentration of 1.1x 10¹² cm-² by Adam Christopher Jandl. Ph. D. in Electronic, Photonic, and Magnetic Materials 2015-08-20T18:47:55Z 2015-08-20T18:47:55Z 2015 2015 Thesis http://hdl.handle.net/1721.1/98164 915603873 eng M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission. http://dspace.mit.edu/handle/1721.1/7582 125 pages application/pdf Massachusetts Institute of Technology |
| spellingShingle | Materials Science and Engineering. Jandl, Adam Christopher III-V compositionally graded buffers for heterostructure integration |
| title | III-V compositionally graded buffers for heterostructure integration |
| title_full | III-V compositionally graded buffers for heterostructure integration |
| title_fullStr | III-V compositionally graded buffers for heterostructure integration |
| title_full_unstemmed | III-V compositionally graded buffers for heterostructure integration |
| title_short | III-V compositionally graded buffers for heterostructure integration |
| title_sort | iii v compositionally graded buffers for heterostructure integration |
| topic | Materials Science and Engineering. |
| url | http://hdl.handle.net/1721.1/98164 |
| work_keys_str_mv | AT jandladamchristopher iiivcompositionallygradedbuffersforheterostructureintegration |