Metal-insulator-metal (MIM) capacitor and fabrication method for making the same

Abstract

A metal-insulator-metal (MIM) capacitor includes a first metal plate; a first capacitor dielectric layer disposed on the first metal plate and a second metal plate stacked on the first capacitor dielectric layer. The first metal plate, the first capacitor dielectric layer, and the second metal plate constitute a lower capacitor. A second capacitor dielectric layer is disposed on the second metal plate. A third metal plate is stacked on the second capacitor dielectric layer. The second metal plate, the second capacitor dielectric layer, and the third metal plate constitute an upper capacitor. The first metal plate and the third metal plate are electrically connected to a first terminal of the MIM capacitor, while the second metal plate is electrically connected to a second terminal of the MIM capacitor.

1 . A metal-insulator-metal (MIM) capacitor, comprising: 
 a first metal plate;    a first capacitor dielectric layer disposed on the first metal plate;    a second metal plate stacked on the first capacitor dielectric layer, wherein the first metal plate, the first capacitor dielectric layer, and the second metal plate constitute a lower capacitor;    a second capacitor dielectric layer disposed on the second metal plate; and    a third metal plate stacked on the second capacitor dielectric layer, wherein the second metal plate, the second capacitor dielectric layer, and the third metal plate constitute an upper capacitor;    and wherein the first metal plate and the third metal plate are electrically connected to a first terminal of the MIM capacitor, while the second metal plate is electrically connected to a second terminal of the MIM capacitor.    
   
   
       2 . The MIM capacitor according to  claim 1  wherein the second metal plate has a surface area that is smaller than that of the first metal plate.  
   
   
       3 . The MIM capacitor according to  claim 1  wherein the third metal plate has a surface area that is smaller than that of the second metal plate.  
   
   
       4 . The MIM capacitor according to  claim 1  wherein the first capacitor dielectric layer is made of PECVD dielectric.  
   
   
       5 . The MIM capacitor according to  claim 1  wherein the second capacitor dielectric layer is made of PECVD dielectric.  
   
   
       6 . The MIM capacitor according to  claim 1  wherein the second metal plate has a thickness that is thinner than that of the first metal plate.  
   
   
       7 . The MIM capacitor according to  claim 6  wherein the second metal plate has a thickness of about 1000 angstroms.  
   
   
       8 . The MIM capacitor according to  claim 6  wherein the second metal plate comprises titanium.  
   
   
       9 - 12 . (canceled)