US 11,677,379 B2
Microelectromechanical resonator
Joseph C. Doll, Mountain View, CA (US); Nicholas Miller, Sunnyvale, CA (US); Charles I. Grosjean, Los Gatos, CA (US); Paul M. Hagelin, Saratoga, CA (US); and Ginel C. Hill, Sunnyvale, CA (US)
Assigned to SiTime Corporation, Santa Clara, CA (US)
Filed by SiTime Coporation, Santa Clara, CA (US)
Filed on Dec. 7, 2021, as Appl. No. 17/544,120.
Application 17/544,120 is a division of application No. 16/245,184, filed on Jan. 10, 2019, granted, now 11,228,298.
Application 16/245,184 is a division of application No. 15/497,146, filed on Apr. 25, 2017, granted, now 10,218,333, issued on Feb. 26, 2019.
Application 15/497,146 is a division of application No. 15/186,510, filed on Jun. 19, 2016, granted, now 9,712,128, issued on Jul. 18, 2017.
Application 15/186,510 is a continuation in part of application No. 14/617,753, filed on Feb. 9, 2015, granted, now 9,705,470, issued on Jul. 11, 2017.
Claims priority of provisional application 62/183,689, filed on Jun. 23, 2015.
Claims priority of provisional application 62/181,767, filed on Jun. 19, 2015.
Claims priority of provisional application 61/937,601, filed on Feb. 9, 2014.
Prior Publication US 2022/0166403 A1, May 26, 2022
Int. Cl. H03H 9/125 (2006.01); H03H 3/007 (2006.01); H03H 9/02 (2006.01); H03H 9/10 (2006.01); H03H 9/24 (2006.01); H03H 9/17 (2006.01); H03H 3/02 (2006.01); H03H 9/15 (2006.01)
CPC H03H 9/125 (2013.01) [H03H 3/0077 (2013.01); H03H 9/02259 (2013.01); H03H 9/02401 (2013.01); H03H 9/02448 (2013.01); H03H 9/1057 (2013.01); H03H 9/17 (2013.01); H03H 9/2463 (2013.01); H03H 2003/027 (2013.01); H03H 2009/02181 (2013.01); H03H 2009/02307 (2013.01); H03H 2009/155 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method of fabricating a microelectromechanical system (MEMS) resonator, the method comprising:
processing a layer of single crystal silicon which is on a semiconductor substrate, so as to fabricate from layer of single crystal silicon each of a body region, an anchor region and a tether, wherein
the layer of single crystal silicon is degenerately-doped with an N-type dopant,
the body region further comprises a layer of piezoelectric material,
the tether is to permit the body region to vibrate relative to the anchor region, under the influence of electrical stimuli applied to the piezoelectric material, and
the body region has a length dimension, the length dimension being oriented so as to have a predetermined, non-zero angular relationship relative to a crystallographic axis of the single crystal silicon;
measuring a resonant frequency of the body region as formed; and
processing the body region, so to adjust at least one property of the body region and thereby adjust the resonant frequency.