Optimizing Pad Conditioning Process

Figure 17 shows the effective density using the elliptic filter with a characteristic length of 2.9 mm. The optimal length must be determined for each consumable set and process conditions since the planarization length is dependent not only on the polish pad type but also on the polish process conditions, notably the down force. 

It is used in IC systems when the amperometric process confers selectivity to the determination of the analytes. The operative modes employed in the amperometric techniques for detection in flow systems include those at (1) constant potential, where the current is measured in continuous mode, (2) at pulsed potential with sampling of the current at dehned periods of time (pulsed amperometry, PAD), or (3) at pulsed potential with integration of the current at defined periods of time (integrated pulsed amperometry, IPAD). Amperometric techniques are successfully employed for the determination of carbohydrates, catecholamines, phenols, cyanide, iodide, amines, etc., even if, for optimal detection, it is often required to change the mobile-phase conditions. This is the case of the detection of biogenic amines separated by cation-exchange in acidic eluent and detected by IPAD at the Au electrode after the post-column addition of a pH modiher (NaOH) [262]. 

In the final analysis, it is the pad-slurry system s performance (under the application and tool conditions) that determines the optimum processing condition. For interlayer dielectric (ILD) oxides, this will often be measured by the removal rate value and uniformity. For other processes, additional metrics, such as dishing and erosion, must be examined for optimization. The evaluation of these additional qualifiers is more complex, because circuit pattern density plays a major role. Often the judgment will include an examination of dishing across a spread of line widths, and an examination of erosion across a spread... 

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