The boron-doped single-crystal diamond allows for the investigation of Schottky barrier diode structures

The successful demonstration of both high and low levels of boron doping allows for the investigation of Schottky barrier diode (SBD) structures, with the intention of optimizing their electronic properties. The heavily boron doped p + -diamond layer is essential for a high quality ohmic contact and low on-state resistance in the forward direction, and the optimization of this layer is needed for the realization of high quality SBD devices. A substrate growth temperature dependence for the formation of unepitaxial crystallites has been shown, which is significant, since unepitaxial crystallites are known to adversely affect SBD performance.

The etch-pit density associated with crystalline dislocations has also been shown to be adversely related to the reverse characteristics of SBDs. Further, the dependence of the reverse current on the size of the Schottky contact area, where the current increases sharply with increasing area,  has led to the general consensus that the threading dislocations which propagate in the growth direction from the heavily boron doped layer are the primary reason for the poor reverse characteristics.Friel  et al.  demonstrated that growing homoepitaxial diamond in a direction perpendicular to the direction of previous epitaxial growth leads to a reduction of screw- and edge-type threading dislocations in the resulting CVD diamond film.

In this work, the method of growing perpendicular to the previous epitaxial direction will  be employed for the growth of the lightly boron doped p - active layer of an SBD, forming a  corner architecture SBD. The corner architecture seeks to minimize the threading dislocations  while simultaneously benefitting from an overall vertical path for the current.

The fabricated  SBDs use gold  (Au) on oxygen terminated diamond as the  Schottky  contacts. Au on oxygenated diamond has been the focus of several recent investigations of  SBD performance, and the quality of the oxygen termination of the diamond surface has  been shown to be critical for device performance, particularly at high temperatures. The oxygenation of the diamond surface was done by oxygen plasma treatment.

The boron-doped single-crystal diamond produced by CSMH can achieve doping from low concentration to high concentration. It has realized a uniform and controllable concentration and a customizable boron doping process.CSMH uses the MPCVD method to prepare large-sized and high-quality diamonds,and currently has mature products such as diamond heat sinks, diamond wafers, diamond windows,diamond hetero junction integrated composite substrates,etc.