Capacitive resonators

Abstract

A micro-electro-mechanical system (MEMS) capacitive resonator and methods for manufacturing the same are invented and disclosed. In one embodiment, an apparatus comprises a micro-electro-mechanical system (MEMS) capacitive resonator, the resonator comprising support means, a semiconductor resonating member coupled to the support means, and electrodes comprised of a different material than the semiconductor resonating member, wherein the electrodes are capacitively coupled to the semiconductor resonating member.

1 . Apparatus comprising: 
 a micro-electro-mechanical system (MEMS) capacitive resonator, comprising: 
 support means;  
 a semiconductor resonating member coupled to the support means; and  
 electrodes comprised of a different material than the semiconductor resonating member, wherein the electrodes are capacitively coupled to the semiconductor resonating member.  
   
   
   
       2 . The apparatus of  claim 1 , further comprising a plurality of MEMS capacitive resonators coupled to the support means.  
   
   
       3 . The apparatus of  claim 1 , wherein the semiconductor resonating member is comprised of single-crystalline silicon.  
   
   
       4 . The apparatus of  claim 1 , wherein the electrodes are comprised of polysilicon.  
   
   
       5 . The apparatus of  claim 1 , wherein the electrodes each comprise a height-to-width ratio greater than 1.  
   
   
       6 . The apparatus of  claim 1 , wherein the electrodes comprise a drive electrode and sense electrode for the resonator.  
   
   
       7 . The apparatus of  claim 1 , wherein the electrodes are configured to receive a varying voltage for tuning the frequency of the resonator.  
   
   
       8 . The apparatus of  claim 1 , further comprising a semiconductor-on-insulator substrate from which at least a portion of the resonator is derived, the substrate electrically isolated from the support means.  
   
   
       9 . The apparatus of  claim 1 , wherein the thickness of the semiconductor resonating member and the electrodes comprise a thickness of approximately 3 microns or greater.  
   
   
       10 . The apparatus of  claim 1 , wherein the semiconductor resonator is configured in an in-plane beam configuration.  
   
   
       11 . The apparatus of  claim 9 , wherein the in-plane beam configuration comprises the semiconductor resonating member configured as a beam, the beam supported by the support means configured as one or more support members, the beam having a defined width and height, the beam configuration comprising the electrodes configured as actuation, sense and tuning electrodes, the electrodes separated from the beam by a sub-micron gap.  
   
   
       12 . The apparatus of  claim 1 , wherein the resonator is configured in a disk configuration.  
   
   
       13 . The apparatus of  claim 12 , wherein the disk configuration comprises the semiconductor resonating member configured as a disk, the disk comprising the support means configured as at least one support member for supporting the disk, the disk having a defined thickness, the disk configuration comprising the electrodes configured as actuation, sense and tuning electrodes, the electrodes separated from the disk by a sub-micron gap.  
   
   
       14 . The apparatus of  claim 13 , wherein the at least one support member is located at a resonance node.  
   
   
       15 . The apparatus of  claim 1 , wherein the resonator is configured in a longitudinal block configuration.  
   
   
       16 . The apparatus of  claim 15 , wherein the block configuration comprises the semiconductor resonating member configured as a longitudinal block, the longitudinal block comprising the support means configured as at least one support member for supporting the block, the block having a defined thickness, the block configuration comprising the electrodes configured as actuation, sense and tuning electrodes, the electrodes separated from the block by a sub-micron gap.  
   
   
       17 . The apparatus of  claim 1 , wherein a gap inherent to the capacitive coupling is formed in a self-aligned manner using a sacrificial layer in between the semiconductor resonating member and each of the electrodes.  
   
   
       18 . A communications device, comprising: 
 a micro-electro-mechanical system (MEMS) capacitive resonator, comprising:    support means;    a semiconductor resonating member coupled to the support means; and    electrodes comprised of a different material than the semiconductor resonating member, wherein the electrodes are capacitively coupled to the semiconductor resonating member.    
   
   
       19 . The device of  claim 18 , further comprising an antenna coupled to the MEMS capacitive resonator.  
   
   
       20 . The device of  claim 18 , wherein the communications device is a portable transceiver.  
   
   
       21 . A micro-electro-mechanical system (MEMS) capacitive resonator configured in an in-plane, longitudinal block configuration, comprising: 
 a semiconductor resonating member configured as a longitudinal block; and    electrodes comprised of a different material than the semiconductor resonating member, wherein the electrodes are capacitively coupled to the semiconductor resonating member,    wherein the longitudinal block is disposed between two clamped regions, the longitudinal block having a defined width and height, the electrodes comprising a drive electrode and a sense electrode, the drive electrode opposed by the sense electrode, the drive electrode separated from the beam by a first sub-micron gap, the sense electrode separated from the beam by a second sub-micron gap.