Bottom up electro deposition and flat surface finishing in micro-trench metal filling process

• Main Author: Guan, Aaron Zhi Xiong.
• Other Authors: School of Mechanical and Aerospace Engineering
• Format: Final Year Project
• Language: English
• Published: 2013
• Subjects: DRNTU::Engineering
• Online Access: http://hdl.handle.net/10356/54076
• Institution: Nanyang Technological University

Metal filling using electrode position usually results in a continuous layer deposition of metal in trenches. This report presents a simple method to achieve a bottom up nickel electrode position with flat surface finishing in micro trenches. A patterned substrate made of silicon wafer patterned by photolithography and gold sputtering process to coat the patterned substrate with a conductive layer were used. The nickel bath were made using Nickel Sulfamate, Nickel Bromide, Nickel Chloride and Boric Acid with a single additive of 10 parts per million (ppm) Polyethylene Glycol (PEG). The patterned substrate were placed into the bath using a customized holder and electroplating were carried out by using only a potentiostat as the electrical power source and paddle agitation unit. The electroplated sample were embedded in acrylic cold mounting resin, then cut and polished using Minitom with EXTEC diamond wafer blade (4") and variable speed grinder-polisher (ECOMET 6, BUEHLER) with abrasive sheets (EXTEC) of grit range from 400 to 4000.