US 11,738,993 B2
Silicon substrate having cavity and cavity SOI substrate including the silicon substrate
Yutaka Kishimoto, Nagaokakyo (JP)
Assigned to MURATA MANUFACTURING CO., LTD., Nagaokakyo (JP)
Filed by Murata Manufacturing Co., Ltd., Nagaokakyo (JP)
Filed on May 27, 2021, as Appl. No. 17/332,167.
Application 17/332,167 is a continuation of application No. PCT/JP2019/047841, filed on Dec. 6, 2019.
Claims priority of application No. 2019-005521 (JP), filed on Jan. 16, 2019.
Prior Publication US 2021/0284524 A1, Sep. 16, 2021
Int. Cl. B81B 1/00 (2006.01); B81C 1/00 (2006.01)
CPC B81B 1/002 (2013.01) [B81C 1/00047 (2013.01); B81B 2203/0315 (2013.01); B81C 2201/0132 (2013.01); B81C 2203/036 (2013.01)] 2 Claims
OG exemplary drawing
 
2. A cavity SOI substrate comprising:
a first silicon substrate having a first surface with a cavity and a second surface opposite the first surface;
a first silicon oxide film having a thickness d1 on the first surface;
a second silicon oxide film having a thickness d2 on a bottom of the cavity;
a third silicon oxide film having a thickness d3 on the second surface; and
a second silicon substrate bonded to the first silicon substrate such that the first silicon oxide film is between the first silicon substrate and the second silicon substrate,
wherein d1≤d3 and d1<d2.