Publication Type:



Volume US5620611 A, Number US 08/659,459 (1997)



Reduced undercutting of a titanium-tungsten layer in a ball limiting metallurgy (BLM) is achieved in the preparation of solder ball interconnect structures by removing metal oxide film which forms on the titanium-tungsten layer and etching the titanium-tungsten layer in different steps. Removing the metal oxide with an acid solution prior to etching the titanium-tungsten layer provides for a more uniform etch of the titanium-tungsten layer.

Cite this Research Publication

M. Datta, Kanarsky, T. S., Pike, M. B., and Shenoy, R. V., “Method to improve uniformity and reduce excess undercuts during chemical etching in the manufacture of solder pads”, U.S. Patent US 08/659,4591997.