Electron transport and heating in silicon dioxide films

摘要

Transport studies in wide bandgap insulators have been limited for many years by the quality of the material. In particular, mobile ions, defects, and trapping sites could control many of the measurable quantities in these films. Because of its importance in the computer and semiconductor industries, amorphous silicon dioxide (SiO2) has evolved over the past 30 years to become the premier insulator in terms of material quality and our understanding of its basic properties. Cleanliness conditions have improved to the extent that particulate and/or ionic contamination (by mobile ions of sodium, potassium, and lithium) no longer limit the quality of oxide layers as they once did. As trapping states in the forbidden bandgap of about 9.5 eV have been related to impurities (such as water) or defects induced during processing (for example, by radiation) and consequently trapping has been minimized, the behavior of this insulator has become more and more ideal in terms of its electrical and physical properties.1