Si-SiO_2 INTERFACE TRAP PROPERTIES AND DEPEDENCE WITH OXIDE THICKNESS AND WITH ELECTRICAL STRESS IN MOSFETS WITH OXIDES IN THE 1-2 NANOMETER RANGE

摘要

In this article, Si-SiO_2 interface trap properties in MOSFET's with oxides in the 1-2 nm range are studied. First, the principle of the charge pumping technique that allowed, for the first time, extraction of Si-SiO_2 interface trap densities, D_(it), from such structures, is recalled. The reliability of the results obtained using this technique is discussed with regard to the hypotheses made in the model used for D_(it) extraction. The approach is validated by using a MOS device having a thick oxide. For devices with ultrathin oxides, the contribution to the results of quantum mechanical effects is addressed. Then, Si-SiO_2 interface trap densities in MOSFET's with oxide thickness between 1.2 and 2.3 nm are measured. From the same measurements, it is shown that the trap capture cross sections are also obtained. The variation of these parameters with oxide thickness are discussed before dealing with their evolution under electrical stress.