Nickel Line Patterning Using Silicon Supersonic Micronozzle Integrated with a Nanoparticle Deposition System

Abstract

In this study, 3-mu m- and 20-nm nickel powders were deposited on Si substrates to pattern a metal line using a nanoparticle deposition system (NPDS) at room temperature. The stand-off distance (SoD), the distance between the substrate and the end of nozzle, was varied from 300 to 1000 mu m to determine its effect on deposition properties. A Ni line was successfully formed on the Si substrate. When 3-mu m Ni powders were used, the thickness of the deposited layer on the Si substrate was measured to be 5.4 mu m, and its width was 176.4 mu m at a SoD of 300 mu m. In contrast, the deposited average thickness at a SoD of 500 mu m was 1.1 mu m, with a width of 190.6 mu m. Moreover, the deposited thickness was measured to be 6.4 mu m using 20-nm Ni powders at a SoD of 300 mu m. Thus, it was found that the deposited thickness decreased as SoD increased, indicating an inversely proportional relationship. For deposition behavior, depending on the size of powders, it was found that 20-nm Ni powders resulted in a thicker deposition than did 3-mu m Ni powders, as momentum transfer between carrier gas and powders is inversely proportional to the powder size. Thus, as the powder size decreased, its spray velocity increased; hence, it is more effective to use nano powders for Ni line patterning. Surface resistivity of the deposited Ni line was 1.83 x 10(-7) Omega.m using 20-nm powders and 1.61 x 10(-7) Omega.m using 3-mu m powders. These values are close to the standard resistivity value for bulk Ni, which is 6.9 x 10(-8) Omega.m, making NPDS a promising technique for metal line-fabrication equipment. (C) 2010 The Japan Society of Applied Physics