Structural origins of intrinsic stress in amorphous silicon thin films
Hydrogenated amorphous silicon (a-Si:H) refers to a broad class of atomic configurations, sharing a lack of long-range order, but varying significantly in material properties, including optical constants, porosity, hydrogen content, and intrinsic stress. It has long been known that deposition condit...
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| Language: | en_US |
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American Physical Society
2012
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| Online Access: | http://hdl.handle.net/1721.1/71270 https://orcid.org/0000-0003-1281-2359 https://orcid.org/0000-0001-8345-4937 |
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| author | Johlin, Eric Carl Castro-Galnares, Sebastián Bertoni, Mariana I. Grossman, Jeffrey C. Buonassisi, Tonio Tabet, Nouar Abdallah, Amir Asafa, Tesleem Said, Syed |
| author2 | Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science |
| author_facet | Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science Johlin, Eric Carl Castro-Galnares, Sebastián Bertoni, Mariana I. Grossman, Jeffrey C. Buonassisi, Tonio Tabet, Nouar Abdallah, Amir Asafa, Tesleem Said, Syed |
| author_sort | Johlin, Eric Carl |
| collection | MIT |
| description | Hydrogenated amorphous silicon (a-Si:H) refers to a broad class of atomic configurations, sharing a lack of long-range order, but varying significantly in material properties, including optical constants, porosity, hydrogen content, and intrinsic stress. It has long been known that deposition conditions affect microstructure, but much work remains to uncover the correlation between these parameters and their influence on electrical, mechanical, and optical properties critical for high-performance a-Si:H photovoltaic devices. We synthesize and augment several previous models of deposition phenomena and ion bombardment, developing a refined model correlating plasma-enhanced chemical vapor deposition conditions (pressure and discharge power and frequency) to the development of intrinsic stress in thin films. As predicted by the model presented herein, we observe that film compressive stress varies nearly linearly with bombarding ion momentum and with a (−1/4) power dependence on deposition pressure, that tensile stress is proportional to a reduction in film porosity, and the net film intrinsic stress results from a balance between these two forces. We observe the hydrogen-bonding configuration to evolve with increasing ion momentum, shifting from a void-dominated configuration to a silicon-monohydride configuration. Through this enhanced understanding of the structure-property-process relation of a-Si:H films, improved tunability of optical, mechanical, structural, and electronic properties should be achievable. |
| first_indexed | 2024-09-23T15:47:47Z |
| format | Article |
| id | mit-1721.1/71270 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T15:47:47Z |
| publishDate | 2012 |
| publisher | American Physical Society |
| record_format | dspace |
| spelling | mit-1721.1/712702022-09-29T16:12:03Z Structural origins of intrinsic stress in amorphous silicon thin films Johlin, Eric Carl Castro-Galnares, Sebastián Bertoni, Mariana I. Grossman, Jeffrey C. Buonassisi, Tonio Tabet, Nouar Abdallah, Amir Asafa, Tesleem Said, Syed Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science Massachusetts Institute of Technology. Department of Materials Science and Engineering Massachusetts Institute of Technology. Department of Mechanical Engineering Massachusetts Institute of Technology. Laboratory for Manufacturing and Productivity Bertoni, Mariana I. Johlin, Eric Carl Castro-Galnares, Sebastián Bertoni, Mariana I. Grossman, Jeffrey C. Buonassisi, Tonio Hydrogenated amorphous silicon (a-Si:H) refers to a broad class of atomic configurations, sharing a lack of long-range order, but varying significantly in material properties, including optical constants, porosity, hydrogen content, and intrinsic stress. It has long been known that deposition conditions affect microstructure, but much work remains to uncover the correlation between these parameters and their influence on electrical, mechanical, and optical properties critical for high-performance a-Si:H photovoltaic devices. We synthesize and augment several previous models of deposition phenomena and ion bombardment, developing a refined model correlating plasma-enhanced chemical vapor deposition conditions (pressure and discharge power and frequency) to the development of intrinsic stress in thin films. As predicted by the model presented herein, we observe that film compressive stress varies nearly linearly with bombarding ion momentum and with a (−1/4) power dependence on deposition pressure, that tensile stress is proportional to a reduction in film porosity, and the net film intrinsic stress results from a balance between these two forces. We observe the hydrogen-bonding configuration to evolve with increasing ion momentum, shifting from a void-dominated configuration to a silicon-monohydride configuration. Through this enhanced understanding of the structure-property-process relation of a-Si:H films, improved tunability of optical, mechanical, structural, and electronic properties should be achievable. National Science Foundation (U.S.) (award ECS- 0335765.) 2012-07-02T13:52:55Z 2012-07-02T13:52:55Z 2012-02 2012-01 Article http://purl.org/eprint/type/JournalArticle 1098-0121 1550-235X http://hdl.handle.net/1721.1/71270 Johlin, Eric et al. “Structural Origins of Intrinsic Stress in Amorphous Silicon Thin Films.” Physical Review B 85.7 (2012). ©2012 American Physical Society https://orcid.org/0000-0003-1281-2359 https://orcid.org/0000-0001-8345-4937 en_US http://dx.doi.org/10.1103/PhysRevB.85.075202 Physical Review B Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. application/pdf American Physical Society APS |
| spellingShingle | Johlin, Eric Carl Castro-Galnares, Sebastián Bertoni, Mariana I. Grossman, Jeffrey C. Buonassisi, Tonio Tabet, Nouar Abdallah, Amir Asafa, Tesleem Said, Syed Structural origins of intrinsic stress in amorphous silicon thin films |
| title | Structural origins of intrinsic stress in amorphous silicon thin films |
| title_full | Structural origins of intrinsic stress in amorphous silicon thin films |
| title_fullStr | Structural origins of intrinsic stress in amorphous silicon thin films |
| title_full_unstemmed | Structural origins of intrinsic stress in amorphous silicon thin films |
| title_short | Structural origins of intrinsic stress in amorphous silicon thin films |
| title_sort | structural origins of intrinsic stress in amorphous silicon thin films |
| url | http://hdl.handle.net/1721.1/71270 https://orcid.org/0000-0003-1281-2359 https://orcid.org/0000-0001-8345-4937 |
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