MgAl2O4 Substrate

Magnesium Aluminate (MgAl2O4 or spinel) single crystalsare widely used for bulk acoustic wave and microwave devices and fast IC epitaxial substrates. MgAl2O4 is an attractive material for uses in a wide range of optical, electronic and structural applications including windows and lenses, which require excellent transmission from the visible through to the mid IR. Theoretical transmission is very uniform and approaches 87% between 0.3 to 5 microns. Transmission characteristics rival that of ALON and sapphire in the mid-wave IR, making it especially attractive for the ever-increasing performance requirements of current and next-generation IR imaging systems. MgAl₂O₄ is a relatively low-cost substrate material, which has been successfully applied to the growth of high quality GaN films. MgAl₂O₄ is cleaved on the (100) plane. GaN LD cavities have been obtained by simply cleaving MgAl₂O₄ substrates along the (100) direction, which will also work well for ZnO. MgAl₂O₄ crystal is very difficult to grow, due to the difficulty in maintaining a single phase structure.