the present oxygen plasma method is used in patterning ruthenium oxide ( ruox ) layers of a sandwich structure 10 of fig1 . the sandwich structure 10 has an uppermost first ruox layer 12 . the sandwich structure 10 also has a pzt ferroelectric layer 14 in contact with the first ruox layer 12 . the sandwich structure 10 further has a second ruox layer 16 in contact with the pzt layer 14 . still further the sandwich structure 10 has a titanium ( ti ) adhesion layer 18 in contact with the second ruox layer 16 . the sandwich structure 10 has a silicon oxide insulator layer 19 in contact with the ti adhesion layer 18 . finally the sandwich structure 10 has a silicon layer 20 in contact with the silicon oxide insulator layer 19 pzt is an alloy that has the general chemical formula pbxzryo3 . pzt is a ternary alloy of lead oxide , zirconium oxide and titanium oxide . the ruox layer 12 , the pzt layer 14 and the ruox layer 16 are 2000 angstroms thick . the ti adhesion layer 18 is 500 angstroms thick . the silicon oxide insulator layer 19 is 4000 angstroms thick . the silicon layer 20 is a base for the other layer of structure 10 . silicon layer 20 can be a section of a thin silicon wafer ( not shown ). the ti adhesion layer 18 is oxidized after it is deposited on the silicon oxide insulator layer 19 . as shown in fig2 , a first titanium - tungsten ( tiw ) alloy layer 22 has been laid down on the first ruox layer 12 , such as by use of a tiw sputtering technique . the first tiw layer 22 is 1200 angstroms thick . a photo - resist film 24 is laid down on the first tiw layer 22 . a photographic mask 26 is placed on the photo - resist film 24 . the photographic mask 26 and photo - resist film 24 are exposed to ultraviolet light . then , the exposed photo - resist film 24 is processed with a photo - resist developer . a photo - resist mask 30 is thus formed on the first tiw layer 22 , as shown in fig3 . fig3 shows the photo resist mask 30 on the first tiw layer 22 . the tiw layer 22 of fig3 is etched with a cf4 plasma in an re machine , to form a first tiw mask 32 , as shown in fig4 . the cf4 plasma forms the first tiw mask 32 . during the etching with a cf4 plasma , the photo - resist mask 30 remains in place , as shown in fig4 . conventional photo - resist image processing techniques are used to transfer the desired photographic pattern of photographic mask 26 into the photo - resist layer 24 that has been deposited on the tiw layer 22 . a photoresist mask 30 is formed on tiw layer 22 as shown in fig3 . a mask pattern , of photo - resist mask 30 , is then transferred into the first tiw layer 22 by an cf4 plasma of a reactive ion etch ( rie ) process in an rie machine 40 ; shown in fig4 a . a first tiw mask 32 is formed from tiw layer 22 , in machine 40 , shown in fig4 a . the conditions used with the rie machine 40 are : cf4 at 112 sccm , o2 at 10 sccm , 100 millitorr pressure , 200 watts of rf power . the etch rate of the tiw layer 22 is 310 angstroms per minute . the first tiw mask 32 is thusly formed on the first ruox layer 12 in rie machine 40 in 3 . 87 minutes . in fig4 the tiw mask 32 is shown as having been formed on an outer surface of the first ruox layer 12 . an oxygen plasma etching method is then used on the tiw masked ruox layer 12 , in rie machine 40 , shown in fig4 a , to pattern the tiw masked ruox layer 12 of fig4 into first ruox electrode 12 a , shown in fig5 . ruox electrode 12 a is formed as a result of the application of the oxygen plasma method to the tiw masked ruox layer 12 , shown in fig4 . the photo - resist mask 30 is removed from the first tiw mask 32 , during application of oxygen plasma to the tiw masked ruox layer 12 ; as shown in fig5 . to obtain the structure shown in fig5 , the sandwich 10 c of fig4 is placed in a chamber 41 of a materials research diode type rie machine 40 , as shown in fig4 a . as shown in fig4 a , oxygen 42 is ionized in the rie machine 40 , to form an oxygen plasma 44 . the oxygen plasma 44 vaporizes unmasked portions of the ruox layer 12 of sandwich 10 c of fig4 . the vaporization is due to an oxidation type chemical reaction of the oxygen plasma 44 with unmasked portions of the ruox layer 12 . a first ruox electrode 12 a , shown in fig5 , is formed from ruox layer 12 , during the oxygen plasma oxidation process . the oxidation reaction that takes place in the chamber 41 of the rie machine 40 is a chemical conversion of unmasked portions of ruox layer 12 into gaseous oxide , such as ruo4 . the preferred system for use in performing the oxidation process is an rie machine 40 . the rie machine 40 is manufactured by materials research corporation and is an rie 61 type plasma machine . the machine 40 has a diode system with a 20 inch diameter chamber 41 , a 16 inch diameter anode 46 and a 12 inch diameter cathode 48 . the sandwich 10 c of fig4 , whose masked ruox layer 12 is to be processed , is placed on the bottom cathode 48 . the cathode 48 is supplied with rf power at 13 . 56 megahertz . vaporization of unmasked portions of the ruox layer 12 is accomplished by introducing oxygen , o2 , at a flow rate of 50 sccm into the chamber 41 of rie plasma machine 40 , adjusting the pumping speed with a throttle valve , to achieve a chamber pressure of 100 millitorr and by applying 300 watts of rf power to the cathode 48 . for the above given parameters in using machine 40 , the etch rate for ruox layer 12 , where x equals 0 . 8 , is 110 angstroms per minute . the ruox layer 12 has a thickness of 2000 angstroms . therefore unmasked portions of ruox layer 12 are removed from pzt layer 14 in 18 . 181 minutes . a tiw masked ru layer , a tiw masked ruo2 layer or a tiw masked ruox layer can be oxygen plasma etched , that is , vaporized , in machine 40 . x can have an integer value or decimal value . the first tiw mask 32 can remain in place while pzt layer 14 is patterned , and while second ruox layer 16 is patterned . alternately , the first tiw mask 32 can be removed from the first ruox electrode 12 a by using a hydrogen peroxide solution at 50 degrees centigrade for 3 minutes . the underlying first ruox electrode 12 a , pzt layer 14 and second ruox layer 16 are unaffected by the hydrogen peroxide . again , the first tiw mask 32 is formed in order to patterning the ruox layer 12 into the first ruox electrode 12 a . a 1200 angstrom thick tiw layer 22 is deposited on the ruox layer 12 and the tiw layer 22 is then masked by photo - resist mask 30 , and etched , in order to form first tiw mask 32 . it is noted that oxygen plasma is a very effective photo - resist mask remover . the etch rate of a photo - resist mask by an oxygen plasma is approximately 1 micrometer per minute . thereafter , pzt layer 14 is masked by a second tiw mask 50 , as shown in fig6 . the second tiw mask 50 is formed in the same manner as described for the formation of first tiw mask 32 of fig4 . a second tiw layer ( not shown ) is used in forming second tiw mask 50 . the masked pzt layer 14 of fig6 is patterned by a plasma etching method using a chloride and fluorocarbon plasma this plasma etching method is disclosed in u . s . pat . no . 5 , 443 , 688 , issued aug . 22 , 1995 . the teaching of the &# 39 ; 688 patent are incorporated herein by reference . as shown in fig7 , a pzt ferroelectric plate 14 a is formed by the etching method of the &# 39 ; 688 patent . a third tiw mask 60 is formed on second ruox layer 16 , as also shown in fig7 . the third tiw mask 60 is formed , on second ruox layer 16 , by the method described above for forming a first tiw mask 32 . the third tiw mask 60 is formed from a third tiw layer ( not shown ). the above described oxygen plasma rie process is applied to masked second ruox layer 16 . an second ruox electrode 16 a is formed , as shown in fig8 , from second ruox layer 16 , shown in fig7 . again , the pzt layer 14 is patterned by a method such described in u . s . pat . no . 5 , 443 , 688 , to form pzt plate 14 a under first ruox electrode 12 a . the lower ruox layer 16 is patterned using an oxygen rie process to form a second ruox electrode 16 a under pzt plate 14 a . the oxygen rie process is described for patterning the first ruox layer 12 that is above pzt layer 14 . the second ruox electrode 16 a , as shown in fig8 , is formed from the lower ruox layer 16 , shown in fig7 . the oxygen plasma rie process is used to etch tiw masked ruox layer 12 and simultaneously remove the photo resist - mask 30 . the tiw mask 32 is unaffected by the oxygen rie process . the tiw mask 32 serves as an effective mask , in a transfer of the tiw mask pattern to the ruox layer 12 . since the tiw mask 32 is unaffected by the oxygen plasma , the tiw mask 32 serves effectively as a mask . the underlying ti adhesion layer 18 , shown in fig8 , is patterned by first depositing a 2800 angstrom thick fourth tiw layer 70 over exposed portions of the ti adhesion layer 18 and over the third tiw mask 60 . a photo - resist layer 72 is placed on the fourth tiw layer 70 . a photographic mask 74 is placed on photo - resist layer 72 . a fourth tiw mask ( not shown ) is formed on the ti adhesion layer 18 . the fourth tiw mask is used in plasma etching the ti adhesion layer 18 . a plasma rie process used to etch the ti adhesion layer 18 . the plasma rie process , for etching ti adhesion layer 18 , uses cc12f2 at 107 sccm , o2 at 1 sccm , 15 millitorr pressure , 100 watts of rf power . the etch rate equals 80 angstroms per minute in the mrc system . thereafter , the tiw masks 32 , 50 , 60 and the fourth tiw mask , are striped away to form a nearly completed pzt ferroelectric capacitor . the stripping , is done by applying a 50 degree centigrade hydrogen peroxide solution to the tiw masks . a completed pzt ferroelectric capacitor 80 is shown in fig9 . electrical lead 82 has been attached to first ruox electrode 12 a . electrical lead 84 has been attached to second ruox electrode 16 a . while the present invention has been disclosed in connection with the preferred embodiment thereof , it should be understood that there are other embodiments which fall within the spirit and scope of the invention as defined by the following claims .