Device grade B-doped homoepitaxial diamond thin films

We review our recent results on properties of high quality B-doped homoepit axial diamond thin films grown by chemical vapor deposition (CVD) by using trimethylboron (TMB) as a B source gas. The conventional (one-step) and the two-step growth methods were used for film preparation. The latter realize d smooth surface without any non-epitaxial crystallites (UCs). The films sh owed a sharp Raman shift peak at 1332 cm(-1), a strong free-excitonic emiss ion at room temperature. and high Hall mobility as high as 1000 cm(2)/Vs or more, indicating high-quality diamond, We also successfully realized resis tivity control of the films in a wide range from 10(0) to 10(5) Omega cm du e to low compensation ratio. Using the two-step growth method, Schottky jun ctions with the ideality factor n of 1.1 or less and undetectable leakage c urrent could be prepared between various metals such as Al, Zn, Cr, Ni, An or Pt and oxidized B-doped CVD diamond films. In particular, we successfull y made nearly ideal Schottky junctions using highly B-doped films in the or der of 10(17) cm(-3) indicating that the quality of the present B-doped fil ms is comparable with or higher than those of conventional semiconductors s uch as Si and GaAs.