3D Integration for VLSI Systems

Chapter 5 TSV FILLING

Arthur Keigler

NEXX Systems

5.1 INTRODUCTION

Copper, tungsten, polysilicon, and nickel are candidate materials TSV conductor filling that are under development. Copper filled TSV is emerging as the most widely adopted structure therefore Cu filling by electrodeposition process is the primary subject of this chapter.

Electrodepostion as a means of filling vias and trenches has been developed since the mid 1990’s as part of the copper damascene process for back end of line (BEOL) wiring so the first section compares in general the TSV and Cu-Damacene filling applications. Electro-filling is a fascinating technology that encompasses diffusion, adsorption, and chemical reaction mechanisms, which have been studied for ...