Resistless microfabrication of Cu thin films on n-type GaAs by projection patterned laser doping using a KrF excimer laser and a SiH4 gas is described. Copper thin films with a linewidth as narrow as 2.35gm are deposited selectively on the doped region by electroplating in a CuSO4 aqueou solution. The resistivity of the deposited Cu films is evaluated to be 2.45x 10° S2cm, which is compared to that of bulk Cu. Using this technique, nonallpyed ohmic contacts can be formed with a specific contact resistance of 2.32x 10a S2 cm 4, which is one-thirtieth of that of the conventional alloyed contacts. The mechanism of Cu film deposition by electroplating is discussed.

Date Published: 23 February 1990
PDF: 8 pages
Proc. SPIE 1190, Laser/Optical Processing of Electronic Materials, (23 February 1990); doi: 10.1117/12.963977

Published in SPIE Proceedings Vol. 1190:
Laser/Optical Processing of Electronic Materials
Jagdish Narayan, Editor(s)