Low-dose SIMOX wafers for LSIs fabricated with internal-thermal-oxidation (ITOX) process: electrical characterization

Electrical performance of separation by implanted oxygen (SIMOX) wafers man ufactured by internal-thermal-oxidation (ITOX) process was evaluated. Break down behaviour of the buried oxide (BOX) layer was confirmed quantitatively to be dominated by Si islands therein, which were found to be reduced in s ize or eliminated by the ITOX process. By optimizing the oxygen dose and IT OX amount, a BOX breakdown field of about 8 MV/cm, comparable to those of t hermally-grown oxide, was attained. The gate oxide integrity on an ITOX-SIM OX wafer was found to be superior to that of bulk Si wafers, indicating the wafer surface was improved by the high temperature annealing.