A Study of Generation-Annealing - Charging of Oxide and Interface Traps in Metal-Oxide - Semiconductor Structure Using Tunneling and Hot Electron Injections

172 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1988.Silicon dioxide has had a dominant role in the integrated circuit technology, particularly in metal-oxide-simiconductor devices where its use as a gate insulator is indispensable. High quality silicon dioxide has been attained by today's semiconductor processing technology. However, as the dimensions of the semiconductor device decrease, the electrical field increases when the supply of voltage stays unchanged. Under the assistance of a high electrical field, a small fraction of electrons can enter the silicon dioxide. The quality of the silicon dioxide will degrade if the trapping of electrons and/or the trap generation by electrons takes place in the silicon dioxide. In order to produce more reliable transistors, better understanding of the basic physics of degradation of the silicon dioxide is needed. The degradation mechanisms of the silicon dioxide are studied in this thesis by using the tunneling and hot electron injections.This study has revealed the following new results. During tunneling electron injection, the generation of interface traps, the generation of positively charged oxide traps, and the increase of negative oxide charges were observed. The electron trapping was found to be near the tunneling electrode, whereas the generation of positively charged traps is far from the tunneling electrode. The correlation between the pileup of phosphorus impurities at the gate/oxide interface and the increase of negative oxide charges near the gate/oxide interface is demonstrated from the process dependencies of trap charging. Low temperature operation enhances the generation rate of traps due to the increase of the electron energy by reducing the electron-phonon scattering probability. Low temperature operation also reduces the annealing rate of negative oxide charges due to the decrease of the thermal emission of electrons in the shallow neutral electron traps.A new experiment is proposed and implemented to study the oxide electric field dependence of the generation rate of oxide and interface traps. It was found that more electron and interface traps are generated at higher oxide electric fields.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD