Fabrication and Electrical Characterization of Low-Temperature Polysilicon Films for Sensor Applications
The development of low-temperature piezoresistive materials provides compatibility with standard silicon-based MEMS fabrication processes. Additionally, it enables the use of such material in flexible substrates, thereby expanding the potential for various device applications. This work demonstrates...
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MDPI AG
2024-12-01
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| author | Filipa C. Mota Inês S. Garcia Aritz Retolaza Dimitri E. Santos Patrícia C. Sousa Diogo E. Aguiam Rosana A. Dias Carlos Calaza Alexandre F. Silva Filipe S. Alves |
| author_facet | Filipa C. Mota Inês S. Garcia Aritz Retolaza Dimitri E. Santos Patrícia C. Sousa Diogo E. Aguiam Rosana A. Dias Carlos Calaza Alexandre F. Silva Filipe S. Alves |
| author_sort | Filipa C. Mota |
| collection | DOAJ |
| description | The development of low-temperature piezoresistive materials provides compatibility with standard silicon-based MEMS fabrication processes. Additionally, it enables the use of such material in flexible substrates, thereby expanding the potential for various device applications. This work demonstrates, for the first time, the fabrication of a 200 nm polycrystalline silicon thin film through a metal-induced crystallization process mediated by an AlSiCu alloy at temperatures as low as 450 °C on top of silicon and polyimide (PI) substrates. The resulting polycrystalline film structure exhibits crystallites with a size of approximately 58 nm, forming polysilicon (poly-Si) grains with diameters between 1–3 µm for Si substrates and 3–7 µm for flexible PI substrates. The mechanical and electrical properties of the poly-Si were experimentally conducted using microfabricated test structures containing piezoresistors formed by poly-Si with different dimensions. The poly-Si material reveals a longitudinal gauge factor (GF) of 12.31 and a transversal GF of −4.90, evaluated using a four-point bending setup. Additionally, the material has a linear temperature coefficient of resistance (TCR) of −2471 ppm/°C. These results illustrate the potential of using this low-temperature film for pressure, force, or temperature sensors. The developed film also demonstrated sensitivity to light, indicating that the developed material can also be explored in photo-sensitive applications. |
| format | Article |
| id | doaj-art-33ba9839fd7e47c0bd3c41ff2660b7f9 |
| institution | Kabale University |
| issn | 2072-666X |
| language | English |
| publishDate | 2024-12-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Micromachines |
| spelling | doaj-art-33ba9839fd7e47c0bd3c41ff2660b7f92025-01-24T13:41:59ZengMDPI AGMicromachines2072-666X2024-12-011615710.3390/mi16010057Fabrication and Electrical Characterization of Low-Temperature Polysilicon Films for Sensor ApplicationsFilipa C. Mota0Inês S. Garcia1Aritz Retolaza2Dimitri E. Santos3Patrícia C. Sousa4Diogo E. Aguiam5Rosana A. Dias6Carlos Calaza7Alexandre F. Silva8Filipe S. Alves9International Iberian Nanotechnology Laboratory, 4715-330 Braga, PortugalInternational Iberian Nanotechnology Laboratory, 4715-330 Braga, PortugalInternational Iberian Nanotechnology Laboratory, 4715-330 Braga, PortugalInternational Iberian Nanotechnology Laboratory, 4715-330 Braga, PortugalInternational Iberian Nanotechnology Laboratory, 4715-330 Braga, PortugalInternational Iberian Nanotechnology Laboratory, 4715-330 Braga, PortugalInternational Iberian Nanotechnology Laboratory, 4715-330 Braga, PortugalInternational Iberian Nanotechnology Laboratory, 4715-330 Braga, PortugalDepartment of Industrial Electronics, University of Minho, 4710-057 Braga, PortugalInternational Iberian Nanotechnology Laboratory, 4715-330 Braga, PortugalThe development of low-temperature piezoresistive materials provides compatibility with standard silicon-based MEMS fabrication processes. Additionally, it enables the use of such material in flexible substrates, thereby expanding the potential for various device applications. This work demonstrates, for the first time, the fabrication of a 200 nm polycrystalline silicon thin film through a metal-induced crystallization process mediated by an AlSiCu alloy at temperatures as low as 450 °C on top of silicon and polyimide (PI) substrates. The resulting polycrystalline film structure exhibits crystallites with a size of approximately 58 nm, forming polysilicon (poly-Si) grains with diameters between 1–3 µm for Si substrates and 3–7 µm for flexible PI substrates. The mechanical and electrical properties of the poly-Si were experimentally conducted using microfabricated test structures containing piezoresistors formed by poly-Si with different dimensions. The poly-Si material reveals a longitudinal gauge factor (GF) of 12.31 and a transversal GF of −4.90, evaluated using a four-point bending setup. Additionally, the material has a linear temperature coefficient of resistance (TCR) of −2471 ppm/°C. These results illustrate the potential of using this low-temperature film for pressure, force, or temperature sensors. The developed film also demonstrated sensitivity to light, indicating that the developed material can also be explored in photo-sensitive applications.https://www.mdpi.com/2072-666X/16/1/57metal-induced crystallizationpolysiliconlow-temperaturegauge factortemperature coefficient of resistancepolyimide |
| spellingShingle | Filipa C. Mota Inês S. Garcia Aritz Retolaza Dimitri E. Santos Patrícia C. Sousa Diogo E. Aguiam Rosana A. Dias Carlos Calaza Alexandre F. Silva Filipe S. Alves Fabrication and Electrical Characterization of Low-Temperature Polysilicon Films for Sensor Applications Micromachines metal-induced crystallization polysilicon low-temperature gauge factor temperature coefficient of resistance polyimide |
| title | Fabrication and Electrical Characterization of Low-Temperature Polysilicon Films for Sensor Applications |
| title_full | Fabrication and Electrical Characterization of Low-Temperature Polysilicon Films for Sensor Applications |
| title_fullStr | Fabrication and Electrical Characterization of Low-Temperature Polysilicon Films for Sensor Applications |
| title_full_unstemmed | Fabrication and Electrical Characterization of Low-Temperature Polysilicon Films for Sensor Applications |
| title_short | Fabrication and Electrical Characterization of Low-Temperature Polysilicon Films for Sensor Applications |
| title_sort | fabrication and electrical characterization of low temperature polysilicon films for sensor applications |
| topic | metal-induced crystallization polysilicon low-temperature gauge factor temperature coefficient of resistance polyimide |
| url | https://www.mdpi.com/2072-666X/16/1/57 |
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