摘要： In this paper, anisotropy of single crystalline silicon (SCS) is exploited to enable side-supported radial-mode thin-film piezoelectric-on-substrate (TPoS) disc resonators. In contrast to the case for isotropic material, it is demonstrated that the displacement of the disc periphery is not uniform for the radial-mode resonance in SCS discs. Specifically, for high order harmonics, nodal points are formed on the edges, creating an opportunity for placing suspension tethers and enabling side-supported silicon disc resonators at very-high-frequency (VHF) band with negligible anchor loss. In order to thoroughly study the effect of material properties and the tether location, anchor loss is simulated using a 3D perfectly-matched-layer (PML) in COMSOL. Through modeling, it is shown that 8th harmonic side-supported SCS disc resonators could potentially have orders of magnitude lower anchor loss in comparison to their nano-crystalline diamond (NCD) disc resonator counterparts given the tethers are aligned to the [100] crystalline plane of silicon. It is then experimentally demonstrated that in thin-film piezoelectric-on-silicon disc resonators fabricated on an 8μm silicon-on-insulator (SOI) wafer, unloaded quality factor improves from ~450 for the second harmonic mode at 43 MHz to ~11,500 for the eighth harmonic mode at 196 MHz if tethers are aligned to [100] plane. The same trend is not observed for NCD disc resonators and SCS disc resonators with tethers aligned to [110] plane. Finally, temperature coefficient of frequency (TCF) is simulated and measured for the radial-mode disc resonators fabricated on the 8μm thick degenerately n-type doped SCS and the TFC data is utilized to guarantee proper identification of the harmonic radial-mode resonance peaks amongst others.