Nitrogen and Silicon Defect Incorporation during Homoepitaxial CVD Diamond Growth on (111) Surfaces
- PDF / 576,684 Bytes
- 6 Pages / 595.22 x 842 pts (A4) Page_size
- 51 Downloads / 196 Views
Nitrogen and Silicon Defect Incorporation during Homoepitaxial CVD Diamond Growth on (111) Surfaces Samuel L. Moore1 and Yogesh K. Vohra1 1 Department of Physics, University of Alabama at Birmingham (UAB), 310 Campbell Hall, 1300 University Boulevard, AL 35294-1170, U.S.A. ABSTRACT Chemical Vapor Deposited (CVD) diamond growth on (111)-diamond surfaces has received increased attention lately because of the use of N-V related centers in quantum computing as well as application of these defect centers in sensing nano-Tesla strength magnetic fields. We have carried out a detailed study of homoepitaxial diamond deposition on (111)-single crystal diamond (SCD) surfaces using a 1.2 kW microwave plasma CVD (MPCVD) system employing methane/hydrogen/nitrogen/oxygen gas phase chemistry. We have utilized Type Ib (111)oriented single crystal diamonds as seed crystals in our study. The homoepitaxially grown diamond films were analyzed by Raman spectroscopy, Photoluminescence Spectroscopy (PL), X-ray Photoelectron Spectroscopy (XPS), Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM). The nitrogen concentration in the plasma was carefully varied between 0 and 1500 ppm while a ppm level of silicon impurity is present in the plasma from the quartz bell jar. The concentration of N-V defect centers with PL zero phonon lines (ZPL) at 575nm and 637nm and the Si-defect center with a ZPL at 737nm were experimentally detected from a variation in CVD growth conditions and were quantitatively studied. Altering nitrogen and oxygen concentration in the plasma was observed to directly affect N-V and Si-defect incorporation into the (111)-oriented diamond lattice and these findings are presented. INTRODUCTION Although excellent quality MPCVD homoepitaxially grown (100)-SCD with highly oriented thick growth layers (several millimeters) with large growth rates on cm2 sized substrates can be realized [1], there are a great many challenges in achieving the same successes with (111)-SCD. These difficulties regularly present themselves when endeavoring to synthesize high quality (111)-SCD growth during MPCVD and are challenging to overcome. One such problem is that crystal faces on (111)-SCD are susceptible to forming surface twins during CVD growth which can detrimentally affect the diamond film's optical and physical properties [2 &references therein]. Another difficulty in producing quality (111)-SCD films is in finding quality seed substrates, as polishing the crystal faces of this orientation is exceedingly difficult and results in large amounts of the material being cleaved away from the surface. Many of the (111)-oriented seed crystals are fabricated via laser cutting thick (100)-oriented crystals, which again leads to a large amount of material being wasted due to the large angle of 54.7o between the (001) and (111) crystal planes [2]. Furthermore the HPHT (111)-SCD's are prone to the formation of dislocations and stacking faults which can ultimately lead to a reduction in CVD growth quality and increased impurity incorporat
Data Loading...
