Cover Image

Samarium oxide and samarium oxynitride thin film gate oxides on silicon substrate / Goh Kian Heng

Sputtered pure samarium (Sm) metal films on silicon substrates were thermally oxidized and oxynitrided at various temperatures (600 – 900 °C) and durations (5 – 20 min). Effects of thermal oxidation ambient in oxygen (O2) and nitrous oxide (N2O) gas ambient on the physical and electrical properti...

Full description

Saved in:
Bibliographic Details
Main Author: Goh, Kian Heng
Format: Thesis
Published: 2017
Subjects:
Q Science (General)
T Technology (General)
Online Access:http://studentsrepo.um.edu.my/7132/4/kian_heng.pdf
http://studentsrepo.um.edu.my/7132/
Tags: Add Tag
No Tags, Be the first to tag this record!
id my.um.stud.7132
record_format eprints
spelling my.um.stud.71322020-03-01T23:33:58Z Samarium oxide and samarium oxynitride thin film gate oxides on silicon substrate / Goh Kian Heng Goh, Kian Heng Q Science (General) T Technology (General) Sputtered pure samarium (Sm) metal films on silicon substrates were thermally oxidized and oxynitrided at various temperatures (600 – 900 °C) and durations (5 – 20 min). Effects of thermal oxidation ambient in oxygen (O2) and nitrous oxide (N2O) gas ambient on the physical and electrical properties of samarium oxide (Sm2O3) and samarium oxynitride (SmxOyNz) thin films were investigated. For all samples oxidized in O2, the XRD patterns showed that crystallinity did not increase with oxidation duration. The crystallinity of Sm2O3 increased as the oxidation temperature increased. Two interfacial layers were observed in high resolution transmission electron microscopy (HRTEM) cross sectional images. The existence of semi-polycrystalline interfacial layers was supported by X-ray diffraction (XRD), Fourier transform infrared (FTIR), Raman analysis, and energy dispersive X-ray (EDX) spectroscopy composition analysis. The activation energy or growth rate of each stacked layer was calculated from Arrhenius plots. A physical model related to semi-polycrystalline interfacial layer is proposed and explained. The smoothest surface of the 700 °C sample showed the best current-voltage (I-V) characteristic. For thermal oxidation in O2, the optimum parameters of oxidation temperature and duration were 700 °C and 15 min, respectively. The optimized sample yielded the best electrical properties with the lowest leakage current (1.15 x 10-4 A cm-2 at 0.71 MV cm-1), highest electrical breakdown field (0.71 MV cm-1), highest barrier height value (2.12 eV), highest trap energy (7.485 x 10-4 eV), lowest trap density (6.88 x 1021 cm-3), highest effective dielectric constant (214), lowest effective oxide charge (2.81 x 1013 cm-2), lowest slow trap charge density (5.56 x 1012 cm-2), lowest average interface trap density (~ 1014 eV-1 cm-2), and lowest total interface trap density (7.31 x 1013 cm-2). For all the samples oxynitrided in N2O, polycrystalline SmxOyNz was formed. Amorphous Sm-silicate (SmaSibOcNd) was embedded between the SmxOyNz film and the Si substrate. The crystallinity of Sm2O3 increased when the oxynitridation temperature increased from 600 ºC to 700 ºC but decreased as the oxynitridation temperature increased to 900 ºC. The weak intensities of Sm2O3 were also detected in FTIR and Raman analysis. According to HRTEM cross sectional images and EDX compositional analysis, only one interfacial layer (SmaSibOcNd) was formed. Similarly, the activation energy or growth rate of each stacked layer was calculated from Arrhenius plots. A physical model related to formation of semi-polycrystalline SmxOyNz thin film and amorphous SmaSibOcNd interfacial layer is suggested and explained. The sample oxynitrided at 700 ºC for 15 min exhibited the best electrical properties with the lowest leakage current (9.54 x 10-7 A cm-2 at 3.9 MV cm-1), highest electrical breakdown field (3.9 MV cm-1), barrier height value (6.33 eV), highest trap energy (0.005 eV), and lowest trap density (5.657 x 1021 cm-3). By comparing the optimized parameters (700 ºC and 15 min) of both oxidized and oxynitrided samples, it showed that the electrical performance is improved by incorporation of nitrogen. The high valance vacancy of nitrogen acts as network former hence stabilizing the oxynitrided structures. 2017-01 Thesis NonPeerReviewed application/pdf http://studentsrepo.um.edu.my/7132/4/kian_heng.pdf Goh, Kian Heng (2017) Samarium oxide and samarium oxynitride thin film gate oxides on silicon substrate / Goh Kian Heng. PhD thesis, University of Malaya. http://studentsrepo.um.edu.my/7132/
institution Universiti Malaya
building UM Library
collection Institutional Repository
continent Asia
country Malaysia
content_provider Universiti Malaya
content_source UM Student Repository
url_provider http://studentsrepo.um.edu.my/
topic Q Science (General)
T Technology (General)
spellingShingle Q Science (General)
T Technology (General)
Goh, Kian Heng
Samarium oxide and samarium oxynitride thin film gate oxides on silicon substrate / Goh Kian Heng
description Sputtered pure samarium (Sm) metal films on silicon substrates were thermally oxidized and oxynitrided at various temperatures (600 – 900 °C) and durations (5 – 20 min). Effects of thermal oxidation ambient in oxygen (O2) and nitrous oxide (N2O) gas ambient on the physical and electrical properties of samarium oxide (Sm2O3) and samarium oxynitride (SmxOyNz) thin films were investigated. For all samples oxidized in O2, the XRD patterns showed that crystallinity did not increase with oxidation duration. The crystallinity of Sm2O3 increased as the oxidation temperature increased. Two interfacial layers were observed in high resolution transmission electron microscopy (HRTEM) cross sectional images. The existence of semi-polycrystalline interfacial layers was supported by X-ray diffraction (XRD), Fourier transform infrared (FTIR), Raman analysis, and energy dispersive X-ray (EDX) spectroscopy composition analysis. The activation energy or growth rate of each stacked layer was calculated from Arrhenius plots. A physical model related to semi-polycrystalline interfacial layer is proposed and explained. The smoothest surface of the 700 °C sample showed the best current-voltage (I-V) characteristic. For thermal oxidation in O2, the optimum parameters of oxidation temperature and duration were 700 °C and 15 min, respectively. The optimized sample yielded the best electrical properties with the lowest leakage current (1.15 x 10-4 A cm-2 at 0.71 MV cm-1), highest electrical breakdown field (0.71 MV cm-1), highest barrier height value (2.12 eV), highest trap energy (7.485 x 10-4 eV), lowest trap density (6.88 x 1021 cm-3), highest effective dielectric constant (214), lowest effective oxide charge (2.81 x 1013 cm-2), lowest slow trap charge density (5.56 x 1012 cm-2), lowest average interface trap density (~ 1014 eV-1 cm-2), and lowest total interface trap density (7.31 x 1013 cm-2). For all the samples oxynitrided in N2O, polycrystalline SmxOyNz was formed. Amorphous Sm-silicate (SmaSibOcNd) was embedded between the SmxOyNz film and the Si substrate. The crystallinity of Sm2O3 increased when the oxynitridation temperature increased from 600 ºC to 700 ºC but decreased as the oxynitridation temperature increased to 900 ºC. The weak intensities of Sm2O3 were also detected in FTIR and Raman analysis. According to HRTEM cross sectional images and EDX compositional analysis, only one interfacial layer (SmaSibOcNd) was formed. Similarly, the activation energy or growth rate of each stacked layer was calculated from Arrhenius plots. A physical model related to formation of semi-polycrystalline SmxOyNz thin film and amorphous SmaSibOcNd interfacial layer is suggested and explained. The sample oxynitrided at 700 ºC for 15 min exhibited the best electrical properties with the lowest leakage current (9.54 x 10-7 A cm-2 at 3.9 MV cm-1), highest electrical breakdown field (3.9 MV cm-1), barrier height value (6.33 eV), highest trap energy (0.005 eV), and lowest trap density (5.657 x 1021 cm-3). By comparing the optimized parameters (700 ºC and 15 min) of both oxidized and oxynitrided samples, it showed that the electrical performance is improved by incorporation of nitrogen. The high valance vacancy of nitrogen acts as network former hence stabilizing the oxynitrided structures.
format Thesis
author Goh, Kian Heng
author_facet Goh, Kian Heng
author_sort Goh, Kian Heng
title Samarium oxide and samarium oxynitride thin film gate oxides on silicon substrate / Goh Kian Heng
title_short Samarium oxide and samarium oxynitride thin film gate oxides on silicon substrate / Goh Kian Heng
title_full Samarium oxide and samarium oxynitride thin film gate oxides on silicon substrate / Goh Kian Heng
title_fullStr Samarium oxide and samarium oxynitride thin film gate oxides on silicon substrate / Goh Kian Heng
title_full_unstemmed Samarium oxide and samarium oxynitride thin film gate oxides on silicon substrate / Goh Kian Heng
title_sort samarium oxide and samarium oxynitride thin film gate oxides on silicon substrate / goh kian heng
publishDate 2017
url http://studentsrepo.um.edu.my/7132/4/kian_heng.pdf
http://studentsrepo.um.edu.my/7132/
_version_ 1738505990460932096
score 13.211869

Similar Items