Effect of boron doping on the surfaces of diamond thin films

Auger and electron energy loss spectroscopies were used to study chemical and structural properties of as‐grown surfaces of boron‐doped diamond thin films prepared by microwave plasma‐assisted chemical vapor deposition. Results are compared to surface properties of as‐deposited undoped diamond thin films. As the boron level in the film increased energy losses associated with π electron bonds (sp² sites) were enhanced at the surface. Similarly, the surface oxygen level of the films increased with increasing boron content. On the other hand the characteristic diamond Raman peak at 1332 cm⁻¹ was narrower than in the undoped films and the broad band at about 1500 cm⁻¹ associated with nondiamond carbon decreased. Surface morphology micrographs obtained from scanning electron microscopy (SEM) measurements indicated that the introduction of boron enhances the appearance of the (111) planes. Surface characterization together with the Raman and SEM results suggest that boron doping enhances surface reactivity resulting in increased adsorption of oxygen and carbonaceous species following the growth process. This behavior has implications on surface treatments necessary for device applications.