BORON-DOPED HOMOEPITAXIAL DIAMOND LAYERS - FABRICATION, CHARACTERIZATION, AND ELECTRONIC APPLICATIONS

For electronic applications. a series of boron-doped homoepitaxial dia mond layers of high crystal quality have been grown on (100)-cut diamo nd substrates using the microwave plasma CVD method. The B-concentrati on varies from 3x10(17) to 3x10(20) atoms/cm(3). The layers are select ively grown into the shape of Hall bars using a sputtered SiO2 mask. T he diamond substrates are 3x3x1 mm(3) in size. Gold wires are bonded t o ohmic contacts on the Hall bars formed by an electron beam evaporate d Mo/Pt/Au sandwich annealed at 950 degrees C for 30 min. Electrical c haracterization is performed in eight samples over the temperature ran ge from 100 to 1300 K. The results are discussed in detail. For diamon d layers grown on synthetic nitrogen-doped (type Ib) substrate, curren t-voltage characteristics of diode type can be observed in the tempera ture range from 360 to 900 degrees C. Green electroluminescent light i s emitted from the p-n junction area. High current Schottky diodes are also fabricated which consist of a gold contact to a moderately B-dop ed homoepitaxial layer grown on a synthetic heavily boron-doped (type IIb) substrate.