Kobe Steel Usa, Inc.

Vasudev Venkatesan

Jesko A Von Windheim

David L Dreifus

Kalyankumar Das

Dale G Thompson, Jr

Alison J Tessmer

Das Kalyankjumar

A rectifying contact for use at high temperatures includes a semiconducting diamond layer and a doped amorphous silicon layer thereon. The amorphous silicon layer may be doped with either a p-type or n-type dopant. The semiconducting diamond may be a doped polycrystalline diamond layer or a natural IIb single crystal diamond. The amorphous silicon layer may be formed by sputter deposition from doped silicon targets. A subsequent heating of the thus formed rectifying contact lowers the forward resistance of the contact by activating additional dopant atoms within the amorphous silicon layer.

Amorphous silicon rectifying contact on diamond and method for making

A chemical sensor includes a diode or a transistor fabricated in diamond. A diamond-based diode chemical sensor includes a first diamond layer of first conductivity type and a second diamond or non-diamond layer of second conductivity type. A relatively highly doped region is formed in the first diamond layer, adjacent an electrical contact to reduce the frequency dependance of the sensor's capacitance/voltage characteristic. A diamond-based transistor sensor includes a controlling electrode such as a gate which is configured to allow a chemical external to the transistor to alter the characteristics of the transistor. Relatively highly doped regions are formed adjacent the transistor's controlling electrodes, such as the source and drain. A heater is thermally coupled to the sensor for heating the sensor to a predetermined operating temperature. A temperature monitor is also coupled to the sensor for monitoring the sensor temperature.

Diamond-based chemical sensors

Schottky diodes and gas sensors include a diamond layer having a Schottky contact thereon and an ohmic contact thereon, wherein the diamond layer includes a highly doped region adjacent the ohmic contact to provide a low resistance ohmic contact. Dramatically reduced frequency dependence of the capacitance/voltage characteristic of Schottky diodes and gas sensors formed thereby, compared to Schottky diodes and gas sensors which do not include the highly doped region adjacent the ohmic contact, is provided. The highly doped region is preferably boron doped at a concentration of at least 10.sup.20 atoms per cubic centimeter to form an ohmic contact with a contact resistance of less than 10.sup.-3 .OMEGA.-cm.sup.2. The ohmic contact is preferably a back contact on the face of the diamond layer opposite the Schottky contact.

Diamond schottky diodes and gas sensors fabricated therefrom

An insulated gate field-effect transistor including an active diamond layer having a desired boron doping concentration profile. The boron doping concentration profile generally decreases with increasing depth into the diamond layer so that the active channel has a doping sufficient for field-effect transistor operation. An insulated gate electrode is formed on the highly doped surface and provides a low gate leakage current and passivates the surface of the diamond layer.

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Raleigh, NC, United States of America

Vasudev Venkatesan