Manufacturing gallium nitride substrates by lateral overgrowth through masks and devices fabricated thereof

A process for producing an epitaxial layer of gallium nitride (GaN) comprising:

• depositing a GaN layer on a substrate;
• depositing a first mask with a plurality of fast openings forming patterns;
• forming a first regrowth of a gallium nitride layer on the said mask under epitaxial conditions;
• forming a second regrowth of gallium nitride, with a doping agent as an enhancer of lateral growth with respect to the vertical growth so as to induce the deposition of gallium nitride features and anisotropic and lateral growth of said features;
• depositing a second mask with a plurality of second openings forming the same patterns as the first openings exactly above the first ones, providing that the pitch of the pattern of the fast openings is exactly identical or twice the pitch of the second openings;
• forming a third regrowth of a gallium nitride layer on the second mask under epitaxial conditions;
• forming a fourth regrowth of gallium nitride, with a doping agent as an enhancer of lateral growth with respect to the vertical growth so as to induce the deposition of gallium nitride features and anisotropic and lateral growth of said features.