Top tri-metal system for silicon power semiconductor devices
AssigneeDiodes Fabtech Inc
InventorRoman Hamerski
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Abstract
A titanium-nickel-palladium solderable metal system for silicon power semiconductor devices (10), which may be used for one or both of the anode (20) or cathode (30). The metal system includes an outer layer of palladium (40,70), an intermediate layer of nickel (50,80), and an inner layer of titanium (60,90). For certain applications, the nickel may be alloyed with vanadium. The metal system may be deposited on bare silicon (100) or on one or more additional layers of metal (110) which may include aluminum, aluminum having approximately 1% silicon, or metal silicide. The use of palladium, rather than gold or silver, reduces cost, corrosion, and scratching.
Claims9
A solderable silicon power semiconductor device including an anode deposited on a silicon substrate, and a cathode deposited on the silicon substrate, the device comprising:
- the anode including:
- an anode outer palladium layer having a thickness approximately between 54×10−3 μm and 66×10−3 μm;
- an anode intermediate nickel layer having a thickness approximately between 198×10−3 μm and 242×10−3 μm, and
- an anode inner titanium layer having a thickness approximately between 99×10−3 μm and 121×10−3 μm, and
- the cathode including:
- a cathode outer palladium layer having a thickness approximately between 54×10−3 μm and 66×10−3 μm;
- a cathode intermediate nickel layer having a thickness approximately between 297×10−3 μm and 363×10−3 μm, and
- a cathode inner titanium layer having a thickness approximately between 135×10−3 μm and 165×10−3 μm.
A solderable silicon power semiconductor device including an anode, a cathode, and a silicon substrate, and one or more additional layers of metal interposed between the silicon substrate and at least one of the anode and the cathode, the device comprising:
- the anode including:
- an anode outer palladium layer having a thickness approximately between 54×10−3 μm and 66×10−3 μm;
- an anode intermediate nickel layer having a thickness approximately between 198×10−3 μm and 242×10−3 μm;
- and
- an anode inner titanium layer having a thickness approximately between 99×10−3 μm and 121×10−3 μm, and
- the cathode including:
- a cathode outer palladium layer having a thickness approximately between 54×10−3 μm and 66×10−3 μm;
- a cathode intermediate nickel layer having a thickness approximately between 297×10−3 μm and 363×10−3 μm, and
- a cathode inner titanium layer having a thickness approximately between 135×10−3 μm and 165×10−3 μm.
Dependencies are inferred from the claim text.