Title :
Optimization of low-pressure nitridation/reoxidation of SiO2 for scaled MOS devices
Author :
Yang, Woodward ; Jayaraman, Raj ; Sodini, Charles G.
Author_Institution :
Dept. of Electr. Eng. & Comput. Sci., MIT, Cambridge, MA, USA
fDate :
7/1/1988 12:00:00 AM
Abstract :
The effect of 950°C low-pressure (0.01- or 0.1-atm) nitridation and low-pressure reoxidation on the electrical properties of thin (12-nm) silicon dioxide films for scaled MOS devices was studied. Turnarounds in fixed positive charge, interface state density, electron trapping, and interface state generation under electrical stress were observed with increasing nitridation. Compare to atmospheric nitridations, the turnarounds occur more gradually in the case of low-pressure nitridation. Low-pressure nitrides oxides also differ from atmospheric nitrided oxides in that a suppression of interface state generation is not normally seen. However, low-pressure nitridation and subsequent reoxidation greatly improves reliability. These attributes in the preturnaround regime of the low-pressure nitridation/reoxidation process were used to optimise the electrical properties of the dielectric
Keywords :
dielectric thin films; insulated gate field effect transistors; semiconductor technology; silicon compounds; 0.01 to 0.1 atm; 12 nm; 950 C; SiO2-Si3N4 films; electrical properties; electrical stress; electron trapping; fixed positive charge; interface state density; interface state generation; low-pressure nitridation; low-pressure reoxidation; process optimisation; reliability; scaled MOS devices; subsequent reoxidation; suppression of interface state generation; turnarounds; Annealing; Dielectric devices; Electron traps; Helium; Indium tin oxide; Interface states; MOS devices; Semiconductor films; Silicon compounds; Stress;
Journal_Title :
Electron Devices, IEEE Transactions on
