Influence of oxygen addition on the crystal shape of CVD boron doped diamond

Abstract

The development of diamond based devices for high power electronic applications requires the growth of thick heavily boron doped diamond. During the growth of CVD single crystals, the final form of the film depends on the different crystalline faces growth rate with respect to each others. Three parameters (α, β and γ) which correspond to the displacement speeds of the {111}, {110} and {113} faces, normalized to the {100} displacement speed can be used into a 3D crystal growth model in order to predict the final crystal morphology. This model has been applied with success to intrinsic diamond, and is extended here to the growth of boron doped diamond. It is found that the addition of diborane gas promotes the appearance of large {110} and {113} faces limiting the usable top surface area and generally leading to stress and consequently to crystal breaking‐up. By adding a small amount of oxygen (0.25%) to the feed gas, the {110} faces appearance can be inhibited and the crystal integrity preserved.

Influence of methane concentration on MPCVD overgrowth of 100‐oriented etched diamond substrates

“…As reported in the literature , the lateral faces of the disk tend to disappear during the overgrowth, for the benefit of the top (0 0 1) face that expands. However, this tendency seems to be different between the SMC and LMC samples.…”

The Effect of Boron Doping Level on The Morphology and Structure of Ultra/Nanocrystalline Diamond Films

“…They noted that, as the oxygen concentration increased to 0.25%, the growth rate decreased because defective sites were formed on graphitic carbon layers, which were potential nucleation sites. Issaoui et al12 have also reported that the addition of a small amount of oxygen (0.25%) with boron can drastically change the growth rates in the different crystallographic directions. They mentioned that it is possible to inhibit the {110} faces formation and obtain a larger top surface area.…”

“…A small amount of oxygen from the solution (boron oxide + methanol) can also contribute to the growth rate variation. Oxygen is known to lead to potential chemical reactions with species in the gas phase and to the consumption of some carbon and boron species in the plasma, which usually reduces the diamond growth rate 12. Das et al13 have studied the effect of oxygen on the growth of non‐doped diamond films.…”

Influence of the Doping Level at Boron Doped Nanocrystalline Diamond Films in the Electrochemical Determination of Nitrite

“…A small amount of oxygen from the solution (B 2 O 3 + methanol) can also contribute to the growth rate variation since with increasing boron doping in the gas mixture, the oxygen also increases. Oxygen is known to lead to potential chemical reactions with species in the gas phase and to the consumption of some carbon and boron species in the plasma, which usually modified the diamond growth rate [9]. The presence of oxygen from the solution in the growth gas mixture could be activated the intermediate species containing oxygen, which enhanced the etch rate of the nondiamond carbon component by improving the quality of the deposited film.…”