Reducing the pressure during the etch step results in a reduction in the length and width of the scallops. The ratio of the narrowest to the widest point of the width of the 3rd scallop is 330:410 nm at 26 mtorr and 360:400 nm for 13 mtorr, in other words a significantly smaller scallops. The length of the third scallop is reduced from 90 nm at 26 mtorr to 60 nm at 13 mtorr. This shows that reducing the initial amount SF 6 in the etch step is an effective way to create small scallops.