Method for porosifying a material and semiconductor structure

A semiconductor structure comprising:

• a porous sub-surface structure of a first III-nitride material;
• and
• a surface layer of a second III-nitride material;
• the surface layer having a charge carrier density of between 1×1014 cm31 3 and 1×1017 cm−3;
• in which the porous sub-surface structure has porosity throughout the porous sub-surface structure, the surface layer having a lateral width and the porous sub-surface structure having a lateral width, in which the lateral width of the surface layer at a narrowest point thereof is more than 550 μm, and in which the lateral width of the porous sub-surface structure at a narrowest point thereof is more than 550 μm.

A semiconductor structure comprising:

• a porous sub-surface structure of a first III-nitride material;
• and
• a non-porous surface layer of a second III-nitride material;
• the surface layer having a charge carrier density of between 1×1014 cm−3 and 1×1017 cm−3;
• in which the porous sub-surface structure is porous throughout the sub-surface structure,
• in which the surface layer has a plurality of lateral dimensions and a minimum lateral dimension which is the smallest of those lateral dimensions,
• in which the porous sub-surface structure has a plurality of lateral dimensions and a minimum lateral dimension which is the smallest of those lateral dimensions,
• in which the minimum lateral dimension of the surface layer is more than 550μm, and in which the minimum lateral dimension of the porous sub-surface structure is more than 550 μm.