Capacitor and its manufacturing method

Abstract

A method for manufacturing a capacitor includes the steps of: sequentially laminating, on a substrate, a lower electrode layer, a dielectric layer and an upper electrode layer; forming a patterned mask layer on the upper electrode layer; patterning at least the upper electrode layer and the ferroelectric layer using the mask layer as a mask; removing the mask layer; and conducting a plasma treatment to contact plasma with an exposed surface of the dielectric layer.

1 . A method for manufacturing a capacitor, comprising the steps of:
 sequentially laminating, on a substrate, a lower electrode layer, a dielectric layer and an upper electrode layer;   forming a patterned mask layer on the upper electrode layer;   patterning at least the upper electrode layer and the ferroelectric layer using the mask layer as a mask;   removing the mask layer; and   conducting a plasma treatment to contact plasma with an exposed surface of the dielectric layer.   
   
   
       2 . A method for manufacturing a capacitor according to  claim 1 , wherein the plasma treatment is conducted at a pressure of 0.26 Pa to 5.0 Pa within a chamber. 
   
   
       3 . A method for manufacturing a capacitor according to  claim 1 , wherein the plasma treatment is conducted at a pressure of 0.26 Pa to 1.0 Pa within a chamber. 
   
   
       4 . A method for manufacturing a capacitor according to  claim 1 , wherein the plasma treatment is conducted with gas including at least one kind selected from N 2 , Ne and He. 
   
   
       5 . A method for manufacturing a capacitor according to  claim 1 , wherein the plasma treatment is conducted with gas including oxygen. 
   
   
       6 . A method for manufacturing a capacitor according to  claim 1 , wherein the plasma treatment is conducted with gas including fluorine. 
   
   
       7 . A method for manufacturing a capacitor according to  claim 1 , wherein a heat treatment is conducted after the plasma treatment. 
   
   
       8 . A method for manufacturing a capacitor according to  claim 1 , wherein a heat treatment is conducted before the plasma treatment. 
   
   
       9 . A method for manufacturing a capacitor according to  claim 1 , comprising the step of forming an insulation layer on an exposed surface of at least the dielectric layer, after the plasma treatment. 
   
   
       10 . A method for manufacturing a capacitor comprising the steps of:
 forming a lower electrode;   forming a dielectric layer composed of a ferroelectric or a piezoelectric above the lower electrode;   forming an upper electrode above the dielectric layer;   patterning the dielectric layer and the upper electrode;   forming a first silicon oxide layer that covers at least a side surface of the dielectric layer;   conducting a treatment with plasma containing oxygen; and   forming a second silicon oxide layer above at least the first silicon oxide layer.   
   
   
       11 . A method for manufacturing a capacitor according to  claim 10 , wherein the plasma containing oxygen further contains nitrogen. 
   
   
       12 . A method for manufacturing a capacitor according to  claim 10 , comprising the step of forming a silicon nitride layer above the first silicon oxide layer after the step of conducting the plasma treatment, and before the step of forming the second silicon oxide layer. 
   
   
       13 . A capacitor comprising:
 a lower electrode;   a dielectric layer composed of a ferroelectric or a piezoelectric provided above the lower electrode;   an upper electrode provided above the dielectric layer;   a first silicon oxide layer that covers at least a side surface of the dielectric layer;   a nitride layer provided above the first silicon oxide layer; and   a second silicon oxide layer provided above at least the nitride layer.   
   
   
       14 . A capacitor according to  claim 13 , further comprising another silicon nitride layer between the nitride layer and the second silicon oxide layer. 
   
   
       15 . A capacitor according to  claim 13 , wherein the nitride layer includes at least one of silicon nitride and silicon oxinitride.