Methods of forming buried electromechanical structures coupled with device substrates and structures formed thereby

Abstract

Methods of forming integrated MEMS structures are described. Those methods and structures may include forming at least one MEMS structure on a first substrate, forming a first bonding layer on a top surface of the first substrate, and then coupling the first bonding layer disposed on the first substrate to a second substrate, wherein the second substrate comprises a device layer. The bonding may comprise a layer transfer process, wherein an integrated MEMS device is formed.

What is claimed is: 
     
         1 . A method of forming a structure comprising:
 forming at least one MEMS structure on a first substrate;   forming a first bonding layer on a top surface of the first substrate; and   coupling the first bonding layer disposed on the first substrate to a second substrate, wherein the coupling is achieved utilizing a layer transfer process, to form an integrated MEMS structure.   
     
     
         2 . The method of  claim 1  further comprising wherein the at least one MEMS structure comprises at least one of a resonator, an actuator, a gyroscope, a sensor, an accelerometer, a compass, a moving element. 
     
     
         3 . The method of  claim 1  further comprising wherein the first substrate comprises a single crystal silicon substrate. 
     
     
         4 . The method of  claim 1  further comprising wherein the first substrate is hermetically sealed utilizing a process above about 1000 degrees Celsius. 
     
     
         5 . The method of  claim 4  further comprising wherein the first substrate is sealed utilizing an epitaxial silicon process, wherein the epitaxial silicon is disposed over substantially the entire top surface of an upper portion of the first substrate. 
     
     
         6 . The method of  claim 1  further comprising wherein the second substrate comprises a device layer. 
     
     
         7 . The method of  claim 1  further comprising wherein the first bonding layer comprises one of a metal and an oxide layer. 
     
     
         8 . The method of  claim 1  further comprising wherein the second substrate comprises a high voltage IC. 
     
     
         9 . The method of  claim 1  further comprising wherein the second substrate comprises one of a CMOS and an RF device. 
     
     
         10 . The method of  claim 1  further comprising wherein the first substrate is bonded to the second substrate by utilizing at least one of an oxide to oxide and a metal to metal layer transfer process. 
     
     
         11 . The method of  claim 1  further comprising wherein the second substrate comprises a second bonding layer disposed on substantially an entire top surface of the second substrate. 
     
     
         12 . A method of forming a structure comprising:
 forming a moveable and a fixed structure in a first substrate;   forming a sacrificial conformal material around the fixed structure and on a top surface of the first substrate;   forming openings in the sacrificial material disposed on the top surface of the first substrate;   forming a high temperature material in the openings;   forming a first bonding layer on the high temperature material; and   layer transferring the first substrate onto a second substrate, wherein the second substrate comprises a device layer.   
     
     
         13 . The method of  claim 12  further comprising wherein the moveable and fixed structures comprise portions of a MEMS device. 
     
     
         14 . The method of  claim 12  further comprising wherein the layer transfer comprises an oxide to oxide layer transfer process. 
     
     
         15 . The method of  claim 12  further comprising wherein the high temperature material comprises an epitaxially grown material. 
     
     
         16 . The method of  claim 12  further comprising wherein the first substrate comprises a silicon on insulator substrate. 
     
     
         17 . The method of  claim 12  further comprising wherein the second substrate comprises a device substrate comprising a second bonding layer on a top surface. 
     
     
         18 . The method of  claim 17  further comprising wherein the second bonding layer is layer transferred to the first bonding layer of the first substrate. 
     
     
         19 . The method of  claim 12  further comprising wherein the device layer comprises one of an RFIC and a high voltage IC. 
     
     
         20 . The method of  claim 12  further comprising wherein the sacrificial material is removed utilizing a vapor HF process. 
     
     
         21 . The method of  claim 12  further comprising wherein a donor wafer is released from the second substrate during the layer transfer process. 
     
     
         22 . The method of  claim 13  further comprising wherein MEMS devices are coupled to the second substrate by forming conductive contacts between portions of individual device structures within the second substrate and the MEMS structures.