Method of depositing dielectric

Abstract

This invention relates to a method of depositing dielectric on a semiconductor substrate to form part of a capacitor. The method includes reactive sputtering a metal oxide layer from a target of metal onto the substrate wherein the support is biased to induce a DC voltage across the depositing dielectric as it forms. The voltage may be in the range of 200-300V.

1 . A method of depositing dielectric on a semiconductor substrate on a support to form part of a capacitor including reactive sputtering a metal oxide layer from a target of the metal onto the substrate characterised in that the support is biased to induce a DC voltage across the depositing dielectric as it forms.  
     
     
         2 . A method as claimed in    claim 1    wherein the induced voltage is in the range 200 to 300 volts.  
     
     
         3 . A method as claimed in    claim 1    or    claim 2    wherein the support is biased by means of an RF or pulsed DC power supply.  
     
     
         4 . A method as claimed in    claim 1    wherein the target is biased by an RF or pulsed DC power supply.  
     
     
         5 . A method as claimed in any one of the preceding claims further including plasma oxidation of the oxide after or during deposition.  
     
     
         6 . A method as claimed in any one of the preceding claims wherein the dielectric is deposited on a first electrode and discrete second electrodes are deposited on the upper surface to define a plurality of capacitors.  
     
     
         7 . A method as claimed in    claim 6    wherein the area of each second electrode is less than 0.01 cm 2 .  
     
     
         8 . A method as claimed in any one of the preceding claims wherein the metal oxide is Tantalum Pentoxide.