ABSTRACT
In the AMT Ar sputtering process, gap distance is an important parameter. It influences the pathway of gas or sputtered particles (molecules or atoms). Sputtering rate will change when the gap distance is varied. Figure 17.22 shows the relationship
between sputtering rate distribution and gap distance under a low system pressure ( p¼ 10mtorr). The distribution of sputtering rate according to radius is not uniform. When the gap distance decreases, the total sputtering rate increases in the focused area. Thus, gap distance plays an important role in achieving a high sputtering rate. At the experimental conditions shown in the figure, the sputtering rate distribution at the center is over 70 A˚/min while a is between zero and 2.0 cm. When a is greater than 2.0 cm, the sputtering rate falls quickly. If a is greater than 4.0 cm (from 4.0 cm to 8.0 cm), the sputtering rate hardly changes with variance of the gap distance.
