nm by plating cmp was conducted using a speedfam ipec type sh 24 apparatus the polisher was used on whose surface plate a polishing pad rodel nitta ic 1400 was attached polishing conditions were as follows a polishing load a contact pressure of the polishing pad 27 6 kpa a rotating speed of the surface plate 55 rpm a carrier rotating speed 55 rpm and a polishing slurry feeding rate 100 ml min polishing rates for a tantalum and a copper films were determined as follows four needle electrodes were aligned on a wafer with a given interval a given current was applied between the outer two probes to detect a potential difference between two inner probes for determining a resistance r u2032 and further the value is multiplied by a correction factor rfc resistivity correction factor to a surface resistivity u03c1s u2032 a surface resistivity u03c1s is determined for a wafer film whose thickness t nm is known the surface resistivity is inversely proportional to the thickness thus when a thickness for a surface resistivity of u03c1s u2032 is d an equation d nm u03c1s u00d7 t u03c1s u2032 holds true using the equation the thickness d can be determined furthermore a variation between before and after polishing was divided by a polishing time to estimate a polishing rate a surface resistivity was determined using mitsubishi chemical industries four probe resistance detector loresta gp as shown in table 1 a polishing slurry was prepared which comprised 5 wt of u03b8 alumina sumitomo chemical industries akp g008 1 5 wt of citric acid kanto chemical co 2 5 wt of h 2 o 2 kanto chemical co and 0 01 to 10 wt of triethanolamine kanto chemical co and whose ph was adjusted to 5 5 with koh.