bta in diw is low bta more readily dissolves in an acidic solution excessive bta residue readily agglomerates forming concentrations or dots of bta over a copper surface after the copper surface has been polished using methods of cmp conventionally bta slurry is expected to be removed applying methods of post cmp clean such as applying a scrubber megasonic and wafer surface spin with the further application of chemical agents and it has been observed that even with the application of steps of post cmp clean a post cmp defect source remains the presence of bta residue conventional methods of polishing a semiconductor surface will next be briefly highlighted in order to provide a better understanding of the invention referring for this purpose specifically to the cross section that is shown in fig1 there is shown a conventional or prior art cmp apparatus wherein a polishing pad 18 is attached to a circular polishing table 10 the polishing table 10 rotates by means of axis 14 in a direction indicated by arrow 22 typically at a rate in the order of 1 to 100 rpm a wafer carrier 12 holds wafer 20 face down against the polishing pad 18 the wafer 20 is typically held in place by applying a vacuum to the backside of the wafer not shown the wafer carrier 12 also rotates as indicated by arrow 24 usually in the same direction as the polishing table 10 at a rate on the order of 1 to 100 rpm due to the rotation 22 of the polishing table 10 the wafer 20 traverses a circular polishing path over the polishing pad 18 a force 25 is also applied in the downward vertical direction against wafer 20 to press the wafer 20 against the polishing pad.