Realization of Three-Dimensionally MEMS Stacked Comb Structures for Microactuators Using Low-Temperature Multi-Wafer Bonding with Self-Alignment Techniques in CMOS-Compatible Processes
A high-aspect-ratio three-dimensionally (3D) stacked comb structure for micromirror application is demonstrated by wafer bonding technology in CMOS-compatible processes in this work. A vertically stacked comb structure is designed to circumvent any misalignment issues that could arise from multiple...
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| Format: | Article |
| Language: | English |
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MDPI AG
2021-11-01
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| Series: | Micromachines |
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| Online Access: | https://www.mdpi.com/2072-666X/12/12/1481 |
| _version_ | 1797502446772158464 |
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| author | Adrian J. T. Teo King Ho Holden Li |
| author_facet | Adrian J. T. Teo King Ho Holden Li |
| author_sort | Adrian J. T. Teo |
| collection | DOAJ |
| description | A high-aspect-ratio three-dimensionally (3D) stacked comb structure for micromirror application is demonstrated by wafer bonding technology in CMOS-compatible processes in this work. A vertically stacked comb structure is designed to circumvent any misalignment issues that could arise from multiple wafer bonding. These out-of-plane comb drives are used for the bias actuation to achieve a larger tilt angle for micromirrors. The high-aspect-ratio mechanical structure is realized by the deep reactive ion etching of silicon, and the notching effect in silicon-on-insulator (SOI) wafers is minimized. The low-temperature bonding of two patterned wafers is achieved with fusion bonding, and a high bond strength up to 2.5 J/m<sup>2</sup> is obtained, which sustains subsequent processing steps. Furthermore, the dependency of resonant frequency on device dimensions is studied systematically, which provides useful guidelines for future design and application. A finalized device fabricated here was also tested to have a resonant frequency of 17.57 kHz and a tilt angle of 70° under an AC bias voltage of 2 V. |
| first_indexed | 2024-03-10T03:33:13Z |
| format | Article |
| id | doaj.art-601dc4265d65420f90d38d41bfe74880 |
| institution | Directory Open Access Journal |
| issn | 2072-666X |
| language | English |
| last_indexed | 2024-03-10T03:33:13Z |
| publishDate | 2021-11-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Micromachines |
| spelling | doaj.art-601dc4265d65420f90d38d41bfe748802023-11-23T09:35:57ZengMDPI AGMicromachines2072-666X2021-11-011212148110.3390/mi12121481Realization of Three-Dimensionally MEMS Stacked Comb Structures for Microactuators Using Low-Temperature Multi-Wafer Bonding with Self-Alignment Techniques in CMOS-Compatible ProcessesAdrian J. T. Teo0King Ho Holden Li1School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, SingaporeSchool of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, SingaporeA high-aspect-ratio three-dimensionally (3D) stacked comb structure for micromirror application is demonstrated by wafer bonding technology in CMOS-compatible processes in this work. A vertically stacked comb structure is designed to circumvent any misalignment issues that could arise from multiple wafer bonding. These out-of-plane comb drives are used for the bias actuation to achieve a larger tilt angle for micromirrors. The high-aspect-ratio mechanical structure is realized by the deep reactive ion etching of silicon, and the notching effect in silicon-on-insulator (SOI) wafers is minimized. The low-temperature bonding of two patterned wafers is achieved with fusion bonding, and a high bond strength up to 2.5 J/m<sup>2</sup> is obtained, which sustains subsequent processing steps. Furthermore, the dependency of resonant frequency on device dimensions is studied systematically, which provides useful guidelines for future design and application. A finalized device fabricated here was also tested to have a resonant frequency of 17.57 kHz and a tilt angle of 70° under an AC bias voltage of 2 V.https://www.mdpi.com/2072-666X/12/12/14813D MEMSwafer bondingCMOS–MEMS compatibilitymultiple wafer stackingalignment error corrections |
| spellingShingle | Adrian J. T. Teo King Ho Holden Li Realization of Three-Dimensionally MEMS Stacked Comb Structures for Microactuators Using Low-Temperature Multi-Wafer Bonding with Self-Alignment Techniques in CMOS-Compatible Processes Micromachines 3D MEMS wafer bonding CMOS–MEMS compatibility multiple wafer stacking alignment error corrections |
| title | Realization of Three-Dimensionally MEMS Stacked Comb Structures for Microactuators Using Low-Temperature Multi-Wafer Bonding with Self-Alignment Techniques in CMOS-Compatible Processes |
| title_full | Realization of Three-Dimensionally MEMS Stacked Comb Structures for Microactuators Using Low-Temperature Multi-Wafer Bonding with Self-Alignment Techniques in CMOS-Compatible Processes |
| title_fullStr | Realization of Three-Dimensionally MEMS Stacked Comb Structures for Microactuators Using Low-Temperature Multi-Wafer Bonding with Self-Alignment Techniques in CMOS-Compatible Processes |
| title_full_unstemmed | Realization of Three-Dimensionally MEMS Stacked Comb Structures for Microactuators Using Low-Temperature Multi-Wafer Bonding with Self-Alignment Techniques in CMOS-Compatible Processes |
| title_short | Realization of Three-Dimensionally MEMS Stacked Comb Structures for Microactuators Using Low-Temperature Multi-Wafer Bonding with Self-Alignment Techniques in CMOS-Compatible Processes |
| title_sort | realization of three dimensionally mems stacked comb structures for microactuators using low temperature multi wafer bonding with self alignment techniques in cmos compatible processes |
| topic | 3D MEMS wafer bonding CMOS–MEMS compatibility multiple wafer stacking alignment error corrections |
| url | https://www.mdpi.com/2072-666X/12/12/1481 |
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