tailieunhanh - Báo cáo hóa học: " Polycrystallization effects on the nanoscale electrical properties of high-k dielectrics"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Polycrystallization effects on the nanoscale electrical properties of high-k dielectrics | Lanza et al. Nanoscale Research Letters 2011 6 108 http content 6 1 108 o Nanoscale Research Letters a SpringerOpen Journal NANO EXPRESS Open Access Polycrystallization effects on the nanoscale electrical properties of high-k dielectrics Mario Lanza Vanessa Iglesias Marc Porti Montse Nafria Xavier Aymerich Abstract In this study atomic force microscopy-related techniques have been used to investigate at the nanoscale how the polycrystallization of an Al2O3-based gate stack after a thermal annealing process affects the variability of its electrical properties. The impact of an electrical stress on the electrical conduction and the charge trapping of amorphous and polycrystalline Al2O3 layers have been also analyzed. Introduction To reduce the excess of gate leakage currents in metal-oxide-semiconductor MOS devices the ultra thin SiO2 gate oxide is replaced by other high-k dielectric materials 1 . However high-k-based devices still show some drawbacks and therefore to have a better knowledge of their properties and to improve their performance a detailed electrical characterization is required. Many researches have been devoted to the study of the electrical characteristics of high-k gate dielectrics mainly using standard wafer level characterization techniques on fully processed MOS capacitors or transistors 1-4 . However since the lateral dimensions of complementary MOS devices are shrinking to a few tens of nanometers or below for a detailed and profound characterization advanced methods with a large lateral resolution are required. In this direction conductive atomic force microscope CAFM as demonstrated for SiO2 and other insulators 5-14 is a very promising tool which allows for a nanometer-resolved characterization of the electrical and topographical properties of the gate oxide. Characterization at the nanoscale allows us to study which factors determine the electrical properties of the dielectric stack and details on how they affect .