Method and device for the controlled electrolytic treatment of thin layers

Abstract

An electric contact in the outer edge thereof, is used for electroplating substrates, e.g. as a wafer in a cup plater. In order to obtain an even electroplating result, at least two electrolytic partial cells are formed which are supplied with current by respective electroplating current sources ( 9 ′) and ( 9 ″) that can be individually adjusted. The partial cathode ( 12 ′) and the associated partial anode ( 7 ′) are supplied in the region of the diametrically remote partial cathode ( 12 ″). Conversely, the partial cathode ( 12 ″) is supplied via the base layer of the partial cathode ( 12 ′). The required levelling of the layer thickness distribution is inter alia carried out by alternate different adjustments of the quantity of the electroplating current of the two partial cells and by the electrodes ( 7,12 ) that rotate relative to each other.

1 . Method for the electrochemical treatment of material ( 1 ) with at least an electrically conductive layer on the treatment side ( 3 ) such as, for example, a global cathode ( 12 ) and a global soluble or insoluble anode ( 7 ), which together form a global electrolytic cell ( 11 ), as well as with electrical contacts ( 10 ) of the material at the edge area, especially for electroplating or etching of substrates, such as a wafer in a cup plater or similar electrolytic processing container, where at least two diametrically arranged pairs of electrolytic partial cells ( 11 ′,  11 ″) are formed in the processing container, consisting of partial electrodes ( 7 ′,  7 ″) and partial counter cathodes ( 12 ′,  12 ″) each of which is supplied with electrolytic current (I) from adjustable current sources ( 9 ′,  9 ″), and where respective current (I) is supplied from the edge section to the material and which is located diametrically opposite on the material to the respective partial cell ( 11 ′,  11 ″). 
     
     
         2 . Method according to  claim 1 , characterized in that in electroplating of the cathodic current (I) and electrolytic etching of the anodic current (I), the material is supplied via the contact area ( 10 ′,  10 ″) located diametrically opposite the respective partial cell ( 11 ′,  11 ″). 
     
     
         3 . Method according to  claim 1 , characterized in that the electrolytic partial cells ( 11 ′ and  11 ″) are alternately supplied as pairs simultaneously or nearly simultaneously with currents of different densities (I). 
     
     
         4 . Method according to  claim 1 , characterized in that the alternation of different currents (I) within the time range of one millisecond is effected for up to half of the total exposure time. 
     
     
         5 . Method according to  claim 1 , characterized in that electrochemical treatment of the material in the center from the alternately switched power sources ( 9 ′,  9 ″) is the preferred treatment. 
     
     
         6 . Method according to  claim 1 , characterized in that the leveling of the resultant preferred central treatment is effected by giving priority to edge electroplating whereby the electrolytic partial cells ( 11 ′ and  11 ″) are electrically connected with one another by means of switch contacts ( 16 ′,  16 ″) with or without a series resistance. 
     
     
         7 . Method according to  claim 1 , characterized in that a rotating or reversing pivoting linear or nonlinear relative motion, including temporary standstill between the material ( 1 ) and the partial anodes ( 7 ′,  7 ″) or partial cathodes ( 12 ′,  12 ″), levels the deposited or etched metal layer. 
     
     
         8 . Device for the electrochemical treatment of material ( 1 ) with at least an electrically conductive layer on the side to be treated ( 3 ) such as, for example, a global cathode ( 12 ) and a global soluble or insoluble anode ( 7 ), which together form a global electrolytic cell ( 11 ), as well as with electrical contacts ( 10 ) of the material at the edge area, especially for electroplating or etching of substrates, such as a wafer in a cup plater or similar electrolytic processing container, using the method according to  claims 1  to  7 , with at least two anodes ( 7 ′,  7 ″), which are arranged diametrically opposite one another, are electrically isolated from one another in the processing container ( 4 ) and are supplied with electroplating current from electroplating current sources ( 9 ′,  9 ″), and where the positive pole of the electroplating current source ( 9 ′) is on the partial anode ( 7 ′) and the negative pole of this electroplating current source ( 9 ′) is on the diametrically opposite edge of the material and is connected via the contact ( 10 ″) while the positive pole of the electroplating current source ( 9 ″) is on the partial anode ( 7 ″) and the negative pole of this electroplating current source ( 9 ″) is on the diametrically opposite edge of the material and is connected via the contact ( 10 ″). 
     
     
         9 . Device according to  claim 8 , characterized in that there is at least one drive for the rotating or reversing pivoting relative movement between the partial electrode ( 7 ′,  7 ″) and the material. 
     
     
         10 . Device according to  claim 8 , characterized in that the switch contacts ( 16 ) are electrically connected to the controlled partial electrodes ( 7 ′,  7 ″) with or without a series resistance.