Patent ID: 7645691

Claim:
A method for forming an ohmic contact and a zener zap diode in an integrated circuit, comprising: providing a semiconductor substrate; forming first, second and third diffusion regions in the semiconductor substrate, the second and third diffusion regions being of opposite polarity types; forming an insulating layer on the semiconductor substrate; forming a first contact opening in the insulating layer to expose the semiconductor substrate, the first contact opening being formed over the first diffusion region; forming a barrier metal layer on the insulating layer and in the first contact opening; forming a second contact opening in the barrier metal layer and the insulating layer to expose the semiconductor substrate, the second contact opening being formed over the second diffusion region; forming a third contact opening in the barrier metal layer and the insulating layer to expose the semiconductor substrate, the third contact opening being formed over the third diffusion region; forming an aluminum layer on the barrier metal layer and the insulating layer and in the first, second and third contact openings; and patterning the aluminum layer to form the ohmic contact over the first diffusion region and the zener zap diode over the second and third diffusion regions.