Semiconductor device and method for manufacturing the same

Abstract

A method for manufacturing a semiconductor device comprises: forming a lower electrode on a semiconductor substrate, sputtering a ferroelectric film on the lower electrode using a target, thermal treating the ferroelectric film in an atmosphere containing oxygen in accordance with an accumulated period of use of the target for fabricating the ferroelectric film, and forming an upper electrode on the ferroelectric film.

1 - 12 . (canceled) 
     
     
         13 . A semiconductor device comprising:
 a semiconductor substrate: and   a ferroelectric capacitor formed on the semiconductor substrate, the ferroelectric capacitor comprising:   a ferroelectric film; and   a pair of electrodes wherein the ferroelectric film is disposed therebetween,   wherein the ferroelectric film is formed using sputtering and thermal treatment in an atmosphere where the amount of oxygen varies in accordance with the accumulated period for a target.   
     
     
         14 . The semiconductor device according to  claim 13 , wherein the oxygen amount used in thermal treating is changed from 40 sccm to 100 sccm in accordance with the accumulated period. 
     
     
         15 . The semiconductor device according to  claim 13 , wherein the thermal treating is RTA (rapid thermal annealing). 
     
     
         16 . The semiconductor device according to  claim 13 , wherein the temperature of the thermal treating is set from 545° C. to 565° C. 
     
     
         17 . The semiconductor device according to  claim 13 , wherein during the first half of the lifetime of the target, the oxygen amount is set from 40 sccm to 60 sccm, and
 during the first half of the lifetime of the target, the oxygen amount is set up from 70 sccm to 100 sccm.   
     
     
         18 . The semiconductor device according to  claim 13 , further including:
 a gate dielectric film formed on the semiconductor substrate,   a gate electrode formed on the gate dielectric film,   an impurity region introduced on the semiconductor substrate, and   a wiring layer formed on the ferroelectric capacitor.   
     
     
         19 . The semiconductor device according to  claim 18 , wherein the gate electrode comprises at least a portion of a word line, and the wiring layer comprises at least a portion of a bit line. 
     
     
         20 . The semiconductor device according to  claim 13 , wherein the semiconductor device is one selected from a group consisting of a stack structure and a planar structure.