Electrical properties of boron-doped diamond films synthesized by MPCVD on an iridium substrate

Abstract Boron-doped diamond films were synthesized on an iridium substrate by microwave plasma-assisted chemical vapor deposition, using trimethylboron as the dopant source. The Ir substrate was bias-treated by the constant-current mode to permit the formation of oriented diamond nuclei. In order to isolate the B-doped diamond layer electrically from the Ir substrate, the non-doped diamond particles that were formed were grown in the 〈1 0 0〉 and then 〈1 1 1〉 directions and finally, a B-doped layer was synthesized to give a B/C ratio of 100–400 ppm. Surface morphology, Hall mobility and hole concentration were investigated for the resulting B-doped diamond films. The Hall mobility was closely related to the surface morphology of the diamond films. After optimizing the synthesis conditions, a Hall mobility of 340 cm−2 V−1 s−1 and hole concentration of 2×1010 at 250 K was obtained for a heteroepitaxial B-doped diamond film synthesized at a B/C ratio of 200 ppm. These values are smaller than previously reported values for homoepitaxial B-doped diamond film.

[1]  H. Okushi.  High quality homoepitaxial CVD diamond for electronic devices , 2001 .

[2]  P. Koidl,et al.  Heteroepitaxial growth of highly oriented diamond on cubic silicon carbide , 1997 .

[3]  K. Kobashi,et al.  Characterization of undoped and boron-doped polycrystalline diamond films synthesized by hot-filament chemical vapor deposition using methanol , 1994 .

[4]  Junzo Tanaka,et al.  Electrical properties of B-doped homoepitaxial diamond (001) film , 1997 .

[5]  Toshiki Tsubota,et al.  Surface morphology and electrical properties of boron-doped diamond films synthesized by microwave-assisted chemical vapor deposition using trimethylboron on diamond (100) substrate , 2000 .

[6]  S. Sonoda,et al.  Electrical Properties of B-doped homoepitaxial diamond films grown from UHP gas sources , 1999 .

[7]  Yoichiro Sato,et al.  Boron concentration dependence of Raman spectra on {100} and {111} facets of B-doped CVD diamond , 1998 .

[8]  J. Field.  The Properties of Diamond , 1979 .

[9]  K. Kusakabe,et al.  Determination of diamond [100] and [111] growth rate and formation of highly oriented diamond film by microwave plasma-assisted chemical vapor deposition , 1995 .

[10]  H. Okushi,et al.  High-Quality B-Doped Homoepitaxial Diamond Films using Trimethylboron , 1998 .

[11]  K. Kusakabe,et al.  Improvement of diamond nuclei orientation by double-step bias treatment in microwave plasma-assisted chemical vapor deposition using C2H4 and CH4 as carbon source , 1997 .

[12]  Toshiki Tsubota,et al.  Heteroepitaxial growth of diamond on an iridium (100) substrate using microwave plasma-assisted chemical vapor deposition , 2000 .

[13]  K. Kusakabe,et al.  Formation of highly oriented diamond film on carburized (100) Si substrate , 1995 .

[14]  J. Glass,et al.  Oriented diamond films grown on nickel substrates , 1993 .

[15]  M. Kitabatake,et al.  Electrical properties of boron-doped diamond films prepared by microwave plasma chemical vapour deposition , 1996 .

[16]  J. Puigdollers,et al.  Trimethylboron doping of CVD diamond thin films , 1994 .

[17]  A. Fujishima,et al.  A study of the crystalline growth of highly boron-doped CVD diamond: preparation of graded-morphology diamond thin films , 2001 .

[18]  Kazuhiro Suzuki,et al.  Epitaxial nucleation of diamond on an iridium substrate by bias treatment, for microwave plasma-assisted chemical vapor deposition , 1998 .

[19]  Kazuhiro Suzuki,et al.  Epitaxial Growth of Diamond on Iridium , 1996 .

[20]  J. Glass,et al.  Textured diamond growth on (100) β‐SiC via microwave plasma chemical vapor deposition , 1992 .

[21]  K. Kusakabe,et al.  Growth behavior of boron-doped diamond in microwave plasma-assisted chemical vapor deposition using trimethylboron as the dopant source , 1998 .

[22]  T. Muto,et al.  Generation of diamond nuclei by electric field in plasma chemical vapor deposition , 1991 .

[23]  M. Schreck,et al.  Diamond/Ir/SrTiO3: A material combination for improved heteroepitaxial diamond films , 1999 .