Copper electroplating Levelers

FIGURE 17.44 The picture on the left shows copper residues that are due to WIWNU. The residues are symmetrical in the middle radius. The right image shows copper residues that are pattern dependent. This wafer has been plated using a first-generation bottom-up fill copper electroplating technique without levelers. 

Pyrobrite [ATOTECH]. TM for a bright-leveling, pyrophosphate copper electroplating process. The materials used are copper pyrophosphate trihydrate, potassium pyrophosphate, ammonium hydroxide, and addition agents. 

This procedure has been utihzed to determine metal cations and anions in water sample [48,50,51], titanium in high-speed steel at a concentration level of 25 3 mg/g [22], heavy metals (20 to 400 mg/1) in electroplating waste waters [25], copper and nickel (5 mg/1) in metal electroplating baths on wedge-shaped plates [44], copper, lead, cadmium, or mercury in vegetable juices [29], and nickel (1 to 3.8 mg/1) in electroplating waste water of lock industries [42,47]. 

Mossbauer sources with convenient lifetimes can be made from Sb, or the 58d isomer of Te. This is evident from the level diagram shown in Figure 1. Single line sources can be made with Sb and 251 if these isotopes are incorporated into materials of cubic symmetry, thereby avoiding quadrupole eflFects. This has been done by electroplating Sb or on a copper foil and annealing (13, 16). Sources have also been made by neutron irradiation of pure Te enriched with (5). The 58-day Te isomer is then produced by neutron... 

Conventional CMP typically requires an overburden of copper of at least 4000 A due to low planarization efficiency. An overburden of 1000 A is sufficient for ECMP to achieve planarization without compromising performance in terms of dishing, erosion, and defectivity. A stress migration test was carried out at 250 °C for 333 h on a structure with metal level 1 and level 2 lines with thickness in the range of 0.14-0.16 pm. An increase in resistance by more than 10% is considered a fail. The reduction in electroplated copper thickness can reduce the number of fails in stress migration test as shown in Table 11.1. 

The more positive electrochemical values favor the formation of reduced species. For example, the Nemst equation predicts that thorium with a half cell potential of E Th = -1.9 V, would have to be at a concentration of over 10 M before it would plate out at the half-cell potential of copper, E° Cu = 0.34 V. Even when a reverse pulse plating process is employed to create level, and polycrystalline, copper, the Nemst equation predicts thorium would still have to be at a concentration of over 10 M before it would plate out at -0.34 V. One would expect to obtain extreme copper purity from contaminants such as Th when electroplating at the voltages required for copper plating. 

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