Crystalline Defects Induced during MPCVD Lateral Homoepitaxial Diamond Growth

Fernando Lloret (1, 2) , David Eon (3) , Etienne Bustarret (3) , Daniel Araujo (1, 2)

1 Dpto Ciencia de los Materiales
2 UCA - Universidad de Cádiz = University of Cádiz
3 NEEL - SC2G - Semi-conducteurs à large bande interdite

The development of new power devices taking full advantage of the potential of diamond has prompted the design of innovative 3D structures. This implies the overgrowth towards various crystallographic orientations. To understand the consequences of such growth geometries on the defects generation, a Transmission Electron Microscopy (TEM) study of overgrown mesa-patterned homoepitaxial microwave plasma enhanced chemical vapor deposition (MPCVD) diamond is presented. Samples have been grown under quite different conditions of doping and methane concentration in order to identify and distinguish the factors involved in the defects generation. TEM is used to reveal threading dislocations and planar defects. Sources of dislocation generation have been evidenced: (i) doping level versus growth plane, and (ii) methane concentration. First source of dislocations has shown to generate <110> Burgers vector dislocations above a critical boron concentration, the second induces <112> type Burgers vector above a critical methane/hydrogen molar ratio. The latter is attributed to partial dislocations whose origin is related to the dissociation of perfect ones by a Shockley process. This dissociation generated stacking faults that likely resulted in penetration twins, also observed on these samples. Lateral growth performed at low methane and boron content did not exhibit any dislocation.

Mots clés: MPCVD; TEM; Selective Growth.; diamond; defects; dislocations; boron-doped diamond; lateral growth; selective growth

Domaines: Science des matériaux [cond-mat.mtrl-sci]

Fernando Lloret, David Eon, Etienne Bustarret, Daniel Araujo. Crystalline Defects Induced during MPCVD Lateral Homoepitaxial Diamond Growth. Nanomaterials, 2018, 8 (10), pp.814. ⟨10.3390/nano8100814⟩. ⟨hal-01931477⟩