Thermal Response and TC f of GaN/AlN Heterostructure Multimode Micro String Resonators From −10 °C Up to 325 °C
Thermal Response and TC f of GaN/AlN Heterostructure Multimode Micro String Resonators From −10 °C Up to 325 °C
复制标题
GaN/AlN 异质结构多模微弦谐振器在 −10 °C 至 325 °C 范围内的热响应和 TC f
DOI:
10.1109/jmems.2021.3089703
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发表时间:
2021
影响因子:
2.7
通讯作者:
P. Feng
中科院分区:
文献类型:
--
作者:
Wen Sui;Xu;Ji;B. Alphenaar;P. Feng
We report on the first experimental characterization and analysis of the thermal response and temperature coefficient of resonance frequency (TC<inline-formula> <tex-math notation="LaTeX">$f$ </tex-math></inline-formula>) of gallium nitride/aluminum nitride (GaN/AlN) heterostructure micro string resonators, in a wide temperature range from −10 °C up to 325 °C. Thanks to its excellent electrical and mechanical properties and chemical inertness, GaN has recently stimulated growing interests in GaN microelectromechanical systems (MEMS) for emerging high-power, high-temperature, and harsh-environment applications. GaN films on Si wafers often require AlN buffer layers, thus the residual tensile stress profile in the GaN epilayers and GaN/AlN hetero-layers can play a key role in affecting the MEMS specifications and performance. Here we design and fabricate GaN/AlN heterostructure micro string resonators with length <inline-formula> <tex-math notation="LaTeX">$L = 100$ </tex-math></inline-formula>, 200 and 300 <inline-formula> <tex-math notation="LaTeX">$\mu \text{m}$ </tex-math></inline-formula> to probe the stress and thermal effects on resonance behavior. All out-of-plane flexural modes show clear string behavior, and the multimode resonance frequencies downshift almost linearly with increasing temperature up to 325 °C. The linear temperature dependence and TC<inline-formula> <tex-math notation="LaTeX">$f$ </tex-math></inline-formula> values of GaN/AlN heterostructure resonators can be directly employed for thermal sensing. Comparison among different devices indicates that higher tensile stress levels contribute to smaller TC<inline-formula> <tex-math notation="LaTeX">$f$ </tex-math></inline-formula> values, suggesting strain engineering may be exploited for intentionally regulating the TC<inline-formula> <tex-math notation="LaTeX">$f$ </tex-math></inline-formula>.