Analysis of selective growth of n-type diamond in lateral p–n junction diodes by cross-sectional transmission electron microscopy

Abstract

The selective growth of n-type diamond on a (001) diamond substrate is a powerful method to obtain a lateral p–n junction diode, which is a basic component of power devices. We analyzed the detailed structure and growth mechanism of the selective growth of n-type diamond by cross-sectional transmission electron microscopy. We observed clear boundary lines between the substrate and the newly grown diamond by the selective growth. Thus, the observation of the n-type diamond was possible despite the homoepitaxial growth. It was revealed that the n-type diamond was synthesized in both the [111] and [110] directions from the bottom of the step corner. On the other hand, the growth in the [001] direction was not observed owing to the controlled growth conditions.