Self-Sealing Complex Oxide Resonators

Abstract

Although 2D materials hold great potential for next-generation pressure sensors, recent studies revealed that gases permeate along the membrane-surface interface, necessitating additional sealing procedures. In this work, we demonstrate the use of free-standing complex oxides as self-sealing membranes that allow the reference cavity beneath to be sealed by a simple anneal. To test the hermeticity, we study the gas permeation time constants in nanomechanical resonators made from SrRuO 3 and SrTiO 3 membranes suspended over SiO 2 /Si cavities which show an improvement up to 4 orders of magnitude in the permeation time constant after annealing the devices. Similar devices fabricated on Si 3 N 4 /Si do not show such improvements, suggesting that the adhesion increase over SiO 2 is mediated by oxygen bonds that are formed at the SiO 2 /complex oxide interface during the self-sealing anneal. Picosecond ultrasonics measurements confirm the improvement in the adhesion by 70% after annealing.

Ultrathin Piezoelectric Resonators Based on Graphene and Free‐Standing Single‐Crystal BaTiO3

“…See ref. [ 12 ] for experimental details. Results of the picosecond ultrasonics measurements are presented in Section S9, Supporting Information.…”

“…Furthermore, single-crystal complex oxides in their ultrathin free-standing form are mechanically robust [7] withstanding large strains up to 8%, [8][9][10] are flexible enough to allow large curvatures [11] and have already been demonstrated as viable nanomechanical resonators. [12][13][14] Simultaneously, the electrodes, which also need to be scaled down, must be able to support high-GHz frequencies for 5G and 6G applications. In this regard, graphene is an ideal electrode material.…”

Research progress of applications of freestanding single crystal oxide thin film

“…(a) Fabrication process of VO 2 using ZnO as the sacrificial layer [76] ; (b) Recorded pulses before and after physical exercise [76] ; (c) Structure diagram of PZT tactile sensor [77] ; (d) and (e) show output signals of touching and bending from PZT tactile sensor [77] . 基于柔性薄膜材料的声波谐振器(Flexible Film Bulk Acoustic Resonator , FFBAR)，实现了高频电路的柔性化，且具有体积小、灵敏度高、功耗低等优 点，在传感与通信领域广泛应用。Lee 等 [81] 展示了自支撑 BTO 薄膜与超薄石墨 图 8 自支撑单晶氧化薄膜在谐振器中的应用。 (a) BTO 薄膜与石墨烯组成的以压电驱动制动 的谐振器实验测试示意图 [81] ；(b) BTO 薄膜与石墨烯谐振器幅值与相位偏移图 [81] ；(c) STO 纳米鼓谐振器谐振模式结果图 [82] ；(d) SRO 纳米鼓谐振器谐振模式结果图 [82] ；STO 退火前(e) 和后(f)中泵探头测量的截面图 [83] ；(g) STO 非退火(黑色)和退火(浅蓝色)的皮秒超声测 量示例 [83] ；(h)对(g)中的波进行傅立叶变换 [83] Fig. 8.…”

“…Applications of freestanding single crystal oxide films in resonators. (a) Schematic and testing diagram of BTO film and graphene based piezoelectric resonator [81] ; (b) Membrane magnitude and phase while sweeping the AC driving frequency [81] ; (c) Test result of STO nano-drum resonator [82] ; (d) Test result of SRO nano-drum resonator [82] ；Cross sectional illustration of the pump-probe measurement in (e) nonannealed STO and (f) annealed STO [83] ; (g)…”

“…of STO [83] ; (h) Fourier transform of the waves in (g) [83] . 图 9 自支撑单晶氧化薄膜在光电传感中的应用。(a)自支撑 Ga 2 O 3 薄膜的制备工艺图 [84] ；(b) 不同光照强度下 Ga 2 O 3 光电探测器的 I-V 结果图 [84] ；(c) Ga 2 O 3 光电探测器 254 nm 光照下的 I-T 曲线 [84] ；(d) NiCo 2 O 4 光电探测器结构图 [85] ；(e) NiCo 2 O 4 光电探测器的 I-V 结果图 [85] ；(f) ZnIn 2 S 4 光电探测器示意图 [86] ； (g) ZnIn 2 S 4 光电探测器在黑暗和照明下测量的 I-V 曲线 [86] ； (h) ZnIn 2 S 4 薄膜制成的可穿戴设备 [86] Fig.…”