Structure comprising a high thermal conductivity boron arsenide layer, and method of manufacture

A method of fabricating a structure for microelectronic applications, comprising:

• providing a 3C polytype silicon carbide layer having a flat surface;
• and
• growing a crystalline boron arsenide BAs layer on the silicon carbide layer, the silicon carbide layer and the crystalline boron arsenide BAs layer having two dimensions each of at least 2 cm respectively along two directions normal to each other and included in an extension plane parallel to the flat surface of the silicon carbide layer.