摘要 |
On the surface of a p-type semiconductor substrate, an n-type diffusion layer is formed. The diffusion layer is in contact with an aluminum wiring via a contact hole formed through an interlayer insulation layer to electrical connection. Immediately beneath the contact portion of the aluminum wiring, a contact n-type diffusion layer having higher impurity concentration than the n-type diffusion layer and having deeper junction depth. Outside of the contact n-type diffusion layer is surrounded by a low impurity concentration n well. With the construction, when an electrostatic pulse is applied to an external terminal connected to the shallow diffusion layer, junction breakdown of the diffusion layer can be successfully prevented.
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