International Rectifier Corporation

Siliconix Technology C. V.

Carmelo Sanfilippo

Rossano Carta

Giovanni Richieri

Paolo Mercaldi

A process for forming a Schottky barrier to silicon to a barrier height selected at a value between 640 meV and 840 meV employs the deposition of a platinum or nickel film atop the silicon surface followed by the deposition of the other of a platinum or nickel film atop the first film. The two films are then exposed to anneal steps at suitable temperatures to cause their interdiffusion and an ultimate formation of NiSi and PtSi contacts to the silicon surface. The final silicide has a barrier height between that of the Pt and Ni, and will depend on the initial thicknesses of the Pt and Ni films and annealing temperature and time. Oxygen is injected into the system to form an SiOpassivation layer to improve the self aligned process.

Process for forming schottky rectifier with PtNi silicide schottky barrier

A process for forming a Schottky barrier to silicon to a barrier height selected at a value between 640 meV and 840 meV employs the deposition of a platinum or nickel film atop the silicon surface followed by the deposition of the other of a platinum or nickel film atop the first film. The two films are then exposed to anneal steps at suitable temperatures to cause their interdiffusion and an ultimate formation of NiSi and PtSi contacts to the silicon surface. The final silicide has a barrier height between that of the Pt and Ni, and will depend on the initial thicknesses of the Pt and Ni films and annealing temperature and time. Oxygen is injected into the system to form and SiO2 passivation layer to improve the self aligned process.

Process for forming Schottky rectifier with PtNi silicide Schottky barrier

A trench type junction barrier rectifier has silicon dioxide spacers at the bottom of trenches in a silicon surface and beneath the bottom of a conductive polysilicon filler in the trench. A Schottky barrier electrode is connected to the tops of the mesas and the tops of the polysilicon fillers. Further oxide spacers may be formed in the length of the polysilicon fillers.

Trench type Schottky rectifier with oxide mass in trench bottom

A trench MOS Schottky barrier device has a metal oxide gate dielectric such as TiSi lining the trench wall to increase the efficiency of the elemental cell and to improve depletion in the mesa during reverse bias. A reduced mask process is used in which a single layer of titanium or other metal is deposited on an underlying gate oxide layer on the trench walls and directly atop the mesa between adjacent trenches. A common thermal treatment causes the Ti to diffuse into the SiOgate oxide to form the TiOgate and to form the TiSi Schottky barrier on the top surface of the mesa.

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Turin, Italy

Carmelo Sanfilippo