US 12,344,524 B2
Methods of fabricating semiconductor structures including cavities filled with a sacrificial material
Mariam Sadaka, Austin, TX (US); and Ludovic Ecarnot, Grenoble (FR)
Assigned to Soitec, Bernin (FR)
Filed by Soitec, Bernin (FR)
Filed on Jul. 6, 2020, as Appl. No. 16/921,675.
Application 16/921,675 is a continuation of application No. 15/328,371, granted, now 10,703,627, previously published as PCT/EP2014/062137, filed on Jun. 11, 2014.
Claims priority of provisional application 61/840,333, filed on Jun. 27, 2013.
Prior Publication US 2020/0331750 A1, Oct. 22, 2020
Int. Cl. B81C 1/00 (2006.01); B81B 1/00 (2006.01)
CPC B81C 1/00047 (2013.01) [B81B 1/002 (2013.01); B81C 1/00158 (2013.01); B81B 2203/0127 (2013.01); B81B 2203/0315 (2013.01); B81C 2201/0105 (2013.01); B81C 2201/014 (2013.01); B81C 2201/0192 (2013.01); H01L 2221/1063 (2013.01); H01L 2224/03001 (2013.01)] 20 Claims
OG exemplary drawing
 
14. A semiconductor device, comprising:
a resonator device selected from the group consisting of a bulk acoustic wave resonator, a surface acoustic wave resonator, and a film bulk acoustic resonator, wherein the resonator device includes:
a substrate comprising a multi-layer structure including a layer of polycrystalline material, one or more surfaces of the substrate defining one or more cavities in the substrate, the one or more cavities extending at least partially into the substrate from a first major surface of the substrate;
a layer of monocrystalline material bonded over the substrate; and
a bonding layer between the layer of monocrystalline material and the substrate, the bonding layer comprising a different material from the polycrystalline material and the monocrystalline material, the bonding layer comprising an oxide material, a nitride material, or a metallic material,
the layer of monocrystalline material defining one or more apertures extending through the layer of monocrystalline material to the one or more cavities in the substrate.