Characteristics of Pulse-Reverse Electrodeposited Cu Thin Films

Abstract

One of the main concerns in fabricating Cu interconnections is a significant increase in resistivity. Thus, pulse-reverse electrodeposition was implemented in an attempt to improve the properties of Cu films. The influences of the anodic step in pulse-reverse electrodeposition were intensively investigated by varying the anodic potential and time (the amount of anodic charge). It was confirmed that the anodic step affected the grain size as well as surface roughness and the change rates of these properties were determined by the anodic potential. The conflicting effects between grain size and surface roughness resulted in the lowest resistivity at an optimum amount of anodic charge. The contributions of the grain size and surface roughness were taken into account to explain the resistivity behavior depending on the anodic charge. A theoretical approach was applied to complement the qualitative findings and it was well-matched with the experimental results.

Degradation of Bis(3-sulfopropyl) Disulfide and Its Influence on Copper Electrodeposition for Feature Filling

“…Organic additives have been extensively employed in Cu electrodeposition to control the properties of deposited Cu films. [1][2][3][4][5][6][7][8][9][10][11][12] Organic additives can be classified as accelerators, suppressors, and levelers in accordance with their influence on the electrochemical behaviors and film properties. [13][14][15] Table I shows the chemical structures of typical additives belonging to each group.…”

Fabrication of Cu-Ag Interconnection Using Electrodeposition: The Mechanism of Superfilling and the Properties of Cu-Ag Film

“…It was observed that the surface roughness of the Cu-Ag film was higher than that of Cu, even though the Cu-Ag film consisted of even smaller grains, which was contributed by the formation of a relatively large groove composed of a few surface grains. 35 The electrical conductivity of Cu, Cu-Ag, and Ag films is presented in Fig. 12a.…”

Pulse-Reverse Electrodeposition of Cu for the Fabrication of Metal Interconnection

“…2e, 2h, 2i, 2l and 2m). 25,26 To quantitatively compare the superfilling performance, the height of Cu deposit from the bottom of the trench was used. The average height could represent the superfilling performance, because the total deposition amount was precisely controlled to 250 mC/cm 2 .…”