Abstract
Passive temperature compensation of silicon MEMS resonators based on heavy n- and p-type doping is studied. Resonators are fabricated utilizing silicon with phosphorus doping level of 5·10 19 cm -3 and boron doping levels of 5·10 19 cm -3 and 2 · 10 20 cm -3 , the latter being stress compensated with germanium. The temperature behavior of the resonance frequencies of Lamé and square extensional (SE) modes is measured. Depending on the vibration mode and crystal orientation, significant temperature compensation effects are observed: as a result of heavy n-type doping the temperature coefficient of frequency (TCF) of the SE mode is reduced from -32 ppm/K to ca. -1 ppm/K, while a Lamé mode resonator exhibits an overcompensated TCF of +18 ppm/K. In p-type resonators a TCF of ca. -2 ppm/K is observed in a Lamé-mode. Keyes' [1] theory of free carrier contribution to the elastic constants of many-valley semiconductors is used to predict the temperature behavior of the n-type resonators. Good agreement is obtained between predicted and observed temperature behavior. The n-type doping can be applied to the TCF reduction of a large class of resonators and shows great potential in improving Si resonator performance.
| Original language | English |
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| Title of host publication | 2011 IEEE International Ultrasonics Symposium |
| Publisher | IEEE Institute of Electrical and Electronic Engineers |
| Pages | 1952-1955 |
| Number of pages | 4 |
| ISBN (Electronic) | 978-1-4577-1252-4, 978-1-4577-1251-7 |
| ISBN (Print) | 978-1-4577-1253-1 |
| DOIs | |
| Publication status | Published - 2011 |
| MoE publication type | Not Eligible |
| Event | IEEE International Ultrasonics Symposium, IUS 2011 - Orlando, United States Duration: 18 Oct 2011 → 21 Oct 2011 |
Conference
| Conference | IEEE International Ultrasonics Symposium, IUS 2011 |
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| Abbreviated title | IUS 2011 |
| Country/Territory | United States |
| City | Orlando |
| Period | 18/10/11 → 21/10/11 |