Method and apparatus for dry etching and electrostatic chucking device used therein

An apparatus for dry etching of a material having at least a conductive portion and using at least a sputter etching apparatus, a reactive sputter etching apparatus or a plasma etching apparatus, comprising:

• (a) a supporting base, the temperature of which is maintained at a predetermined value;
• (b) an electrostatic chuck mounted on the supporting base for chucking the material to be dry etched and having,
• (i) a sheet of insulator positioned on the top surface of said electrostatic chuck and,
• (ii) a pair of plane electrodes positioned on the bottom surface of said sheet of insulator in close contact with said sheet, wherein said pair of plane electrodes is electrically isolated from each other, the sum of the area of the portions of said pair of plane electrodes facing the direction of said material being approximately equal to the contact area between said material and said sheet of insulator when said material is chucked, voltage being supplied between said pair of plane electrodes from an external voltage source so that said material can be chucked on said sheet of insulator;
• and
• (c) an etching chamber wherein gases are applied with electric power to form a plasma for etching.

A method for dry etching of a material having at least a conductive portion, using at least one of a sputter etching apparatus, a reactive sputter etching apparatus or a plasma etching apparatus, comprising the steps of:

• (a) putting the material to be etched on an electrostatic device having,
• (i) a sheet of insulator, and
• (ii) a pair of plane electrodes positioned on the bottom surface of said sheet of insulator in close contact with said sheet, wherein said pair of plane electrodes is electrically isolated from each other, voltage being supplied between said pair of plane electrodes from an external voltage source to cause the material to be chucked on the top surface of said sheet of insulator, the electrostatic device being positioned on a supporting base, the temperature of which is maintained at a predetermined value, and the sum of the area of the portions of said pair of plane electrodes facing the direction of said material is approximately equal to the contact area between said material and said sheet of insulator when said material is chucked,
• (b) applying a voltage between said pair of plane electrodes of said electrostatic device from the external power source to cause said material to be chucked electrostatically and thereby indirectly fixed to said supporting base;
• (c) introducing etching gases into the etching chamber of one of said sputter etching apparatus, said reactive sputter etching apparatus, or said plasma etching apparatus and applying an electric field to said gases by another power source to form a plasma, and
• (d) etching of said material at the condition of high heat conductivity between said material and said supporting base, said high heat conductivity being obtained by the electrostatic chucking force resulting in an increase in thermal contact therebetween, whereby the temperature of said material is controlled close to said predetermined value.