Silicon on aluminum nitride structures formed by wafer bonding

This paper deals with the use of reactively sputtered aluminum nitride (AlN) films as insulators for Bond and Etch-back Silicon-On-Insulator (BESOI) materials. In SOI-applications where high power is dissipated in the silicon SOI-film the low thermal conductivity of the buried silicon dioxide layer may cause a temperature rise in the silicon film detrimentally affecting the device performance. An attractive alternative would be to replace the silicon dioxide of the SOI structure with another material, like diamond, silicon carbide or aluminum nitride. The thermal conductivity of AlN is considerably larger than that of Si0₂. This paper presents results on how sputter deposition of AlN may be combined with wafer bonding for the creation of highly thermally conductive SOI structures