Glass-based SOI structures

A semiconductor-on-insulator layered structure comprising a substantially single-crystal semiconductor material (material S) and an oxide glass or an oxide glass-ceramic which comprises positive ions (material G), wherein at least a part of the structure comprises in order:

• material S;
• material S with an enhanced oxygen content;
• material G with a reduced modifier positive ion concentration;
• material G with an enhanced modifier positive ion concentration;
• and
• material G,
• wherein the material G with the reduced modifier positive ion concentration is operable to inhibit ion re-migration from the material G into the material S.

A semiconductor-on-insulator layered structure, comprising:

• a first layer of substantially single-crystal semiconductor material;
• a second layer of substantially single-crystal semiconductor material with an enhanced oxygen content located on the first layer;
• and
• a substrate of an oxide glass or an oxide glass-ceramic having:
• (i) a first substrate layer adjacent the second layer of substantially single-crystal semiconductor material, the first substrate layer having a reduced positive ion concentration in which substantially no modifier positive ions are present, and (ii) a second substrate layer adjacent the first substrate layer and having an enhanced positive ion concentration of modifier positive ions, including at least one alkaline earth modifier ion.