Deep hole traps in boron-doped diamond

Deep hole traps in boron-doped diamond epitaxial layers are studied by means of several types of deep-level transient spectroscopy and density-functional theory calculations. Standard deep-level transient spectroscopy and high-resolution isothermal transient spectroscopy permit to identify nine deep hole traps. Their capture cross-sections and ionization energies are systematically determined. In parallel, the ionization energies of donor and acceptor levels related to boron- and/or hydrogen-related complexes in diamond are assessed by ab initio calculations in this work and summarized with others from the literature including native defects. Tentative assignments of the measured deep hole traps to the calculated ones are proposed. I. INTRODUCTION Defects in semiconductors not only influence the electri- cal and optical properties of these materials but they also exhibit their own interesting physics. The identification and control of defects such as interstitials, vacancies, light atoms impurities like H or N in diamond, and their complex with host atoms is a major field of research, with important appli- cations in materials engineering. Defects have been studied using a wide range of experimental techniques as electron paramagnetic resonance spectroscopy, 1,2 Hall conductivity, 3,4 positron annihilation, 5 and deep-level transient spectroscopy DLTS. 6-8 Diamond is still a very attractive material because of its exceptional physical and electronic properties. 9-11 In particu- lar, diamond exhibits high carriers mobilities, 12-14 break- down strength, 15 and thermal conductivity, 16 which enable diamond to surpass other wide band-gap materials for high- power and high-frequency electronic applications. However, the electronic properties of diamond are limited by defects and impurities introduced during the growth process and subsequent processing steps in the device fabrication. There- fore, improvement of the knowledge about this issue needs to understand and determine the electronic properties and lattice structures of defects and/or impurities in the diamond matrix.