Method of forming a sensor for detecting motion

Abstract

A method of forming a sensor for detecting motion is disclosed. The method includes a first step ( 110 ) of providing a silicon-on-insulator (SOI) substrate ( 200 ) containing a device layer ( 210 ), an insulator layer ( 220 ), and a handle layer ( 230 ). The device layer may be patterned to form a device structure ( 310 ). A support substrate ( 410 ) is also provided and patterned, and an electrically conductive layer ( 510 ) is formed over the support substrate. The SOI substrate and the support substrate are bonded together, and the handle layer and the insulator layer are removed from the SOI substrate, thus releasing the device structure.

What is claimed is:  
     
         1 . A method of forming a MEMS device, the method comprising: 
 providing a silicon-on-insulator substrate comprising a device layer, an insulator layer, and a handle layer;    patterning the device layer to form a device structure in the device layer;    providing a support substrate;    patterning the support substrate;    forming an electrically conductive layer over the support substrate;    bonding together the silicon-on-insulator substrate and the support substrate;    removing the handle layer from the silicon-on-insulator substrate; and    removing the insulator layer from the silicon-on-insulator substrate.    
     
     
         2 . The method of  claim 1  further comprising: 
 forming an integrated circuit in the device layer; and  
 electrically coupling the integrated circuit to the device structure.  
 
     
     
         3 . The method of  claim 1  wherein: 
 forming the electrically conductive layer over the support substrate comprises: 
 providing the electrically conductive layer comprised of aluminum.  
 
 
     
     
         4 . The method of  claim 1  wherein: 
 forming the electrically conductive layer over the support substrate comprises: 
 providing the electrically conductive layer comprised of gold.  
 
 
     
     
         5 . The method of  claim 1  wherein: 
 forming the electrically conductive layer over the support substrate comprises: 
 providing the electrically conductive layer comprised of doped polysilicon.  
 
 
     
     
         6 . The method of  claim 1  wherein: 
 bonding together the silicon-on-insulator substrate and the support substrate further comprises: 
 using an anodic bonding technique to bond together the silicon-on-insulator substrate and the support substrate.  
 
 
     
     
         7 . The method of  claim 1  wherein: 
 bonding together the silicon-on-insulator substrate and the support substrate further comprises: 
 using a surface activated bonding technique to bond together the silicon-on-insulator substrate and the support substrate.  
 
 
     
     
         8 . A method of manufacturing a MEMS device, the method comprising: 
 providing a silicon-on-insulator substrate comprising a device layer, an insulator layer, and a handle layer;    patterning the device layer to form a seismic mass in the device layer;    providing a support substrate;    patterning the support substrate;    forming an electrically conductive layer over the support substrate;    bonding together the silicon-on-insulator substrate and the support substrate;    removing the handle layer from the silicon-on-insulator substrate; and    removing the insulator layer from the silicon-on-insulator substrate.    
     
     
         9 . The method of  claim 8  wherein: 
 providing the support substrate further comprises: 
 providing the support substrate comprised of glass.  
 
 
     
     
         10 . The method of  claim 8  wherein: 
 providing the support substrate further comprises: 
 providing the support substrate comprised of quartz.  
 
 
     
     
         11 . The method of  claim 8  wherein: 
 providing the support substrate further comprises: 
 providing the support substrate comprised of silicon with an overlying insulating layer.  
 
 
     
     
         12 . The method of  claim 8  wherein: 
 providing the silicon-on-insulator substrate further comprises: 
 providing the device layer comprised of silicon.  
 
 
     
     
         13 . The method of  claim 8  wherein: 
 removing the insulator layer further comprises: 
 using a dry etchant to remove the insulator layer from the silicon-on-insulator substrate.  
 
 
     
     
         14 . The method of  claim 8  wherein: 
 the sensor is an accelerometer.  
 
     
     
         15 . The method of  claim 8  wherein: 
 the sensor is a gyroscope.  
 
     
     
         16 . The method of  claim 8  wherein: 
 the sensor is a switch.  
 
     
     
         17 . The method of  claim 8  further comprising: 
 forming an integrated circuit in the device layer; and  
 electrically coupling the integrated circuit to the seismic mass.  
 
     
     
         18 . A method of manufacturing a sensor for detecting motion, the method comprising: 
 providing a silicon-on-insulator substrate comprising a device layer and a handle layer separated from each other by an insulator layer;    etching a first pattern into the device layer to form a cantilever structure in the device layer;    providing a support substrate having a surface;    etching a second pattern into the surface of the support substrate;    forming an electrically conductive layer over the surface of the support substrate after etching the second pattern;    bonding together the device layer of the silicon-on-insulator substrate and the surface of the support substrate after etching the first pattern and after forming the electrically conductive layer;    etching the handle layer from the silicon-on-insulator substrate after bonding together the device layer of the silicon-on-insulator substrate and the surface of the support substrate; and    etching the insulator layer from the silicon-on-insulator substrate after removing the handle layer to release the cantilever structure.    
     
     
         19 . The method of  claim 18  wherein: 
 etching the handle layer further comprises: 
 using the insulator layer as an etch stop when etching the handle layer.  
 
 
     
     
         20 . The method of  claim 18  wherein: 
 providing the silicon-on-insulator substrate further comprises: 
 providing the handle layer comprised of silicon; and  
 providing the insulator layer comprised of an oxide;  
 
 forming the electrically conductive layer further comprises: 
 providing the electrically conductive layer comprised of aluminum; and  
 
 etching the insulator layer further comprises: 
 using a dry etchant to etch the insulator layer.  
 
 
     
     
         21 . The method of  claim 18  wherein: 
 bonding together the device layer of the silicon-on-insulator substrate and the surface of the support substrate further comprises:  
 using an anodic bonding technique to bond together the device layer of the silicon-on-insulator substrate and the surface of the support substrate.  
 
     
     
         22 . The method of  claim 18  wherein: 
 bonding together the device layer of the silicon-on-insulator substrate and the surface of the support substrate further comprises: 
 using a surface activated bonding technique to bond together the device layer of the silicon-on-insulator substrate and the surface of the support substrate.