Electrode structure and semiconductor device
AssigneesSanyo Semiconductor Co., Ltd., Semiconductor Components Industries, LLC
InventorsKikuo Okada, Kojiro Kameyama, Takahiro Oikawa
Life of this patent
Estimating the term…
Abstract
In a power MOS transistor, for example, a source electrode is formed so as to be commonly connected to a plurality of source regions formed on the front surface. Thus, a current density varies based on in-plane resistance of the source electrode, thereby providing the necessity of increasing the number of wires connecting the sources and a lead. In the invention, an electrode structure includes a copper plating layer 10e formed on a pad electrode 10a by an electrolytic plating method, and a nickel plating layer 10f and a gold plating layer formed so as to cover the upper and side surfaces of the copper plating layer 10e by an electroless plating method.
Claims6
A semiconductor device comprising:
- a plurality of operation cells formed in a semiconductor substrate;
- a first electrode disposed on a front surface of the semiconductor substrate so as to be connected to the operation cells, the operation cells being configured to allow current flows in a vertical direction of the semiconductor substrate;
- and
- a first external connection terminal electrically connected to the first electrode at a bonding portion,
- wherein the first electrode comprises a copper plating layer and a cover layer covering a side surface of the copper plating layer, and the cover layer does not cover a top surface of the copper plating layer and comprises a metal layer for preventing oxidation of the copper plating layer.
Dependencies are inferred from the claim text.