Nitrogen Defect Concentration in Chemical Vapor Deposited Homoepitaxial Diamond at High TemperatureS

Abstract

AbstractHomoepitaxial diamond films were grown on polished single crystal {100} oriented natural type Ila diamond circular substrates using high density microwave plasma chemical vapor deposition (MPCVD). Twelve homoepitaxial diamond films were grown under a variety of substrate temperatures (1000 C-2000 C), methane concentration (1% - 3% in hydrogen gas) and processing pressure(60 - 150 torr). Electron paramagnetic resonance (EPR) studies demonstrate that nitrogen is largely incorporated as singly substitutional impurity (P1-center) and nitrogen's concentration is in the range of 10 -100 parts per million. Nitrogen's concentration also shows a systematic decrease with increasing substrate temperatures. The temperature variation of nitrogen at high temperatures is discussed within a model where single substitutional nitrogen aggregates to form nitrogen defects which are not EPR active.