Temperature dependence of the work function of ruthenium-based gate electrodes

H. N. Alshareef; H. C. Wen; H. F. Luan; K. Choi; H. R. Harris; Y. Senzaki; P. Majhi; B. H. Lee; B. Foran; G. Lian

doi:10.1016/j.tsf.2006.03.026

Temperature dependence of the work function of ruthenium-based gate electrodes

H. N. Alshareef^*, H. C. Wen, H. F. Luan, K. Choi, H. R. Harris, Y. Senzaki, P. Majhi, B. H. Lee, B. Foran, G. Lian

^*Corresponding author for this work

Research output: Contribution to journal › Article › peer-review

10 Scopus citations

Abstract

The effect of device fabrication temperature on the work function of ruthenium (Ru) metal gate and its bilayers was investigated. The work function shows strong temperature dependence when Ru electrodes are deposited on silicon oxide, SiO₂, but not on hafnium silicates (HfSiO_x). Specifically, the work function of Ru on SiO₂ increased from 4.5 eV at 500 °C to 5.0 eV at 700 °C. On further annealing to 900 °C or higher, the work function dropped to about 4.4 eV. In the case of HfSiO_x, the work function of Ru changed by less than 100 mV over the same temperature range. Identical temperature dependence was observed using hafnium (Hf)/Ru and tantalum (Ta)/Ru bilayers. However, the peak values of the work function decreased with increasing Hf/Ru and Ta/Ru thickness ratios. Materials analysis suggests that these trends are driven by interactions at the Ru metal gate-dielectric interface.

Original language	English (US)
Pages (from-to)	1294-1298
Number of pages	5
Journal	Thin Solid Films
Volume	515
Issue number	4
DOIs	https://doi.org/10.1016/j.tsf.2006.03.026
State	Published - Dec 5 2006
Externally published	Yes

Keywords

Gate electrodes
Hafnium silicon oxide
Ruthenium
Work function

ASJC Scopus subject areas

Electronic, Optical and Magnetic Materials
Surfaces and Interfaces
Surfaces, Coatings and Films
Metals and Alloys
Materials Chemistry

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10.1016/j.tsf.2006.03.026

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title = "Temperature dependence of the work function of ruthenium-based gate electrodes",

abstract = "The effect of device fabrication temperature on the work function of ruthenium (Ru) metal gate and its bilayers was investigated. The work function shows strong temperature dependence when Ru electrodes are deposited on silicon oxide, SiO2, but not on hafnium silicates (HfSiOx). Specifically, the work function of Ru on SiO2 increased from 4.5 eV at 500 °C to 5.0 eV at 700 °C. On further annealing to 900 °C or higher, the work function dropped to about 4.4 eV. In the case of HfSiOx, the work function of Ru changed by less than 100 mV over the same temperature range. Identical temperature dependence was observed using hafnium (Hf)/Ru and tantalum (Ta)/Ru bilayers. However, the peak values of the work function decreased with increasing Hf/Ru and Ta/Ru thickness ratios. Materials analysis suggests that these trends are driven by interactions at the Ru metal gate-dielectric interface.",

keywords = "Gate electrodes, Hafnium silicon oxide, Ruthenium, Work function",

author = "Alshareef, {H. N.} and Wen, {H. C.} and Luan, {H. F.} and K. Choi and Harris, {H. R.} and Y. Senzaki and P. Majhi and Lee, {B. H.} and B. Foran and G. Lian",

year = "2006",

month = dec,

day = "5",

doi = "10.1016/j.tsf.2006.03.026",

language = "English (US)",

volume = "515",

pages = "1294--1298",

journal = "Thin Solid Films",

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TY - JOUR

T1 - Temperature dependence of the work function of ruthenium-based gate electrodes

AU - Alshareef, H. N.

AU - Wen, H. C.

AU - Luan, H. F.

AU - Choi, K.

AU - Harris, H. R.

AU - Senzaki, Y.

AU - Majhi, P.

AU - Lee, B. H.

AU - Foran, B.

AU - Lian, G.

PY - 2006/12/5

Y1 - 2006/12/5

N2 - The effect of device fabrication temperature on the work function of ruthenium (Ru) metal gate and its bilayers was investigated. The work function shows strong temperature dependence when Ru electrodes are deposited on silicon oxide, SiO2, but not on hafnium silicates (HfSiOx). Specifically, the work function of Ru on SiO2 increased from 4.5 eV at 500 °C to 5.0 eV at 700 °C. On further annealing to 900 °C or higher, the work function dropped to about 4.4 eV. In the case of HfSiOx, the work function of Ru changed by less than 100 mV over the same temperature range. Identical temperature dependence was observed using hafnium (Hf)/Ru and tantalum (Ta)/Ru bilayers. However, the peak values of the work function decreased with increasing Hf/Ru and Ta/Ru thickness ratios. Materials analysis suggests that these trends are driven by interactions at the Ru metal gate-dielectric interface.

AB - The effect of device fabrication temperature on the work function of ruthenium (Ru) metal gate and its bilayers was investigated. The work function shows strong temperature dependence when Ru electrodes are deposited on silicon oxide, SiO2, but not on hafnium silicates (HfSiOx). Specifically, the work function of Ru on SiO2 increased from 4.5 eV at 500 °C to 5.0 eV at 700 °C. On further annealing to 900 °C or higher, the work function dropped to about 4.4 eV. In the case of HfSiOx, the work function of Ru changed by less than 100 mV over the same temperature range. Identical temperature dependence was observed using hafnium (Hf)/Ru and tantalum (Ta)/Ru bilayers. However, the peak values of the work function decreased with increasing Hf/Ru and Ta/Ru thickness ratios. Materials analysis suggests that these trends are driven by interactions at the Ru metal gate-dielectric interface.

KW - Gate electrodes

KW - Hafnium silicon oxide

KW - Ruthenium

KW - Work function

UR - http://www.scopus.com/inward/record.url?scp=33750832896&partnerID=8YFLogxK

U2 - 10.1016/j.tsf.2006.03.026

DO - 10.1016/j.tsf.2006.03.026

M3 - Article

AN - SCOPUS:33750832896

SN - 0040-6090

VL - 515

SP - 1294

EP - 1298

JO - Thin Solid Films

JF - Thin Solid Films

IS - 4

ER -

Temperature dependence of the work function of ruthenium-based gate electrodes

Abstract

Keywords

ASJC Scopus subject areas

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