Modification and reduction of defects in thin gate dielectric of MIS devices by injection‐thermal and irradiation treatments

Abstract

The effect of high‐field injection‐thermal and irradiation treatments on the MIS structures reliability and defect reduction in the nanoscale gate dielectric has been investigated. Injection‐thermal treatment (ITT) of MIS structures consisted of high‐field electron injection into gate dielectric with the charge of defined value and subsequent parameter stabilization of MIS structures by means of thermal annealing. The MIS structures have been studied using novel techniques of multilevel current stress. Our study shows that the ITT can improve reliability of MIS structures (increase of charge‐to‐breakdown value) and identify defective structures. The ITT provides structural modification of SiO2 and Si–SiO2 interfaces. It has been shown that the ITT at elevated temperatures can reduce the reliability of MIS devices. Performing ITT at high temperatures leads to decrease of charge‐to‐breakdown average value in MIS structures. It has been demonstrated that irradiation treatment allows to reduce density of defects in thermal SiO2 films, SiO2 films doped with phosphorus, oxynitride films and as a result to increase reliability of MIS devices. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Modification of MIS Devices by Irradiation and High-Field Electron Injection Treatments

“…Accumulation of required density of the thermostable component of negative charge inside the gate dielectric (1) and those with the SiO2-PSG two-layer gate dielectric (2,3) when PSG is of different thickness: 2 -9 nm, 3 -22 nm.…”

“…Figure 3 shows the histograms of MIS structures distribution by charge injected into the dielectric until breakdown when the current stress [1,5] for the samples with the SiO 2 gate dielectric (1) and those with the SiO 2 -PSG gate dielectric (2,3). Figure 3 shows that the usage of the SiO 2 -PSG two-layer gate dielectric allows to rise the average amount of charge injected into the dielectric until breakdown and to diminish a number of defective structures with low charge-to-breakdown.…”

“…In order to make the injection modification of MIS structures, high-field tunnel injection of electrons from the substrate [1][2][3][4] was applied in the mode of flowing of constant injection current with the density of 0.1 µA/cm 2 to 10 mA/cm 2 . During the injection, monitoring of voltage dropped on the MIS structure was applied.…”

“…This parameter determines characteristics and reliability of MIS structures. An important problem of modern micro-and nanoelectronics is developing of technologies and methods to correct parameters of MIS structures not only during their production, but also during their operation [1][2][3][4]. In order to accomplish this, it is necessary to develop new nanosized dielectric films and structures based on them, whose features allow to modify their charge state in a wide range of values and keep that modified charge state for a long time.…”

“…In order to accomplish this, it is necessary to develop new nanosized dielectric films and structures based on them, whose features allow to modify their charge state in a wide range of values and keep that modified charge state for a long time. Multilayer dielectric films, including the SiO 2 film doped with phosphorus, are promising for these purposes [2,4].…”