Study of the positive charge buildup into buried oxide of SIMOX SOI structure during bias-temperature stress

The buildup of fixed and mobile charge in the buried oxide (BOX) of silicon implanted by oxygen (SIMOX) silicon-on-insulator (SOI) structures during bias-temperature (BT) cycling has been studied by the thermally stimulated polarization (TSP) current technique and C-V measurements. Two polarization processes have been observed: the first process with activation energy of 0.3 eV is likely related to the positively charged ion transport across the BOX, the second process with activation energy about 1.2 eV is associated with space charge polarization. It was found that the ion transport is created simultaneously with the process of lateral positive charge buildup near the BOX/substrate interface when the bias is applied to the structure at temperatures above 280oC.