ELECTRICAL PROPERTIES OF METAL-BURIED OXIDE-SILICON STRUCTURES FABRICATED BY LOW DOSE SIMOX PROCESS

摘要

Metal-buried oxide-silicon structures were fabricated for electrical and structural evaluation of buried oxide (BOX) synthesised by Low Dose SIMOX process. The total BOX/Si substrate interface charge was ～3x10~(10) cm~(-2) while the density of interface states was D~(it) (cm~(-2) eV~(-1)) ≈ 5Xl0~(12). The substrate doping profile was found to be unaffected by the high temperature process needed for SIMOX fabrication. A minority carrier trap was detected by Deep Level Transient Spectroscopy (DLTS). This trap is seated ～300meV above the valence band and is probably due to stacking faults lying near the interface. By applying Generation-DLTS, the minority carrier generation lifetime at different temperatures was estimated. The calculated values are in the order of 10~(-2)-10~(-1) * s and suggest a degraded quality of the area below the BOX. The results obtained here are compared with those reported for high dose SIMOX material.