Evaluation method for grown-in dislocations in CVD single crystal diamond using plasma surface treatment

Etch pits were formed on the surface of a freestanding CVD homoepitaxial (001)-oriented diamond film using an oxygen and hydrogen (O/H) plasma. Nomarski images of the film surface after such plasma treatment and transmission birefringence images with butterfly-shaped strain patterns induced by dislocations in the film were compared. The obtained results suggested that each etch pit individually corresponds to each threading dislocation line. The number of dislocation lines in the grown-in dislocation bundle in the CVD diamond was evaluated by counting the number of etch pits aggregating around the dislocation bundle. (C) 2014 The Japan Society of Applied Physics