The Effects of Nitrogen on Electrical and Structural Properties in TaSixNy/SiO2/p-Si MOS Capacitors

2002 ◽  
Vol 716 ◽  
Author(s):  
You-Seok Suh ◽  
Greg Heuss ◽  
Jae-Hoon Lee ◽  
Veena Misra

AbstractIn this work, we report the effects of nitrogen on electrical and structural properties in TaSixNy /SiO2/p-Si MOS capacitors. TaSixNy films with various compositions were deposited by reactive sputtering of TaSi2 or by co-sputtering of Ta and Si targets in argon and nitrogen ambient. TaSixNy films were characterized by Rutherford backscattering spectroscopy and Auger electron spectroscopy. It was found that the workfunction of TaSixNy (Si>Ta) with varying N contents ranges from 4.2 to 4.3 eV. Cross-sectional transmission electron microscopy shows no indication of interfacial reaction or crystallization in TaSixNy on SiO2, resulting in no significant increase of leakage current in the capacitor during annealing. It is believed that nitrogen retards reaction rates and improves the chemical-thermal stability of the gate-dielectric interface and oxygen diffusion barrier properties.

1999 ◽  
Vol 595 ◽  
Author(s):  
A. Vantomme ◽  
M.F. Wu ◽  
S. Hogg ◽  
G. Langouche ◽  
K. Jacobs ◽  
...  

AbstractRutherford backscattering and channeling spectrometry (RBS), photoluminescence (PL) spectroscopy and transmission electron microscopy (TEM) have been used to investigate macroscopic and microscopic segregation in MOCVD grown InGaN layers. The PL peak energy and In content (measured by RBS) were mapped at a large numberof distinct points on the samples. An indium concentration of 40%, the highest measured in this work, corresponds to a PL peak of 710 nm, strongly suggesting that the lightemitting regions of the sample are very indium-rich compared to the average measured by RBS. Cross-sectional TEM observations show distinctive layering of the InGaN films. The TEM study further reveals that these layers consist of amorphous pyramidal contrast features with sizes of order 10 nm. The composition of these specific contrast features is shown to be In-rich compared to the nitride matrix.


2000 ◽  
Vol 5 (S1) ◽  
pp. 703-709
Author(s):  
A. Vantomme ◽  
M.F. Wu ◽  
S. Hogg ◽  
G. Langouche ◽  
K. Jacobs ◽  
...  

Rutherford backscattering and channeling spectrometry (RBS), photoluminescence (PL) spectroscopy and transmission electron microscopy (TEM) have been used to investigate macroscopic and microscopic segregation in MOCVD grown InGaN layers. The PL peak energy and In content (measured by RBS) were mapped at a large number of distinct points on the samples. An indium concentration of 40%, the highest measured in this work, corresponds to a PL peak of 710 nm, strongly suggesting that the light-emitting regions of the sample are very indium-rich compared to the average measured by RBS. Cross-sectional TEM observations show distinctive layering of the InGaN films. The TEM study further reveals that these layers consist of amorphous pyramidal contrast features with sizes of order 10 nm. The composition of these specific contrast features is shown to be In-rich compared to the nitride matrix.


1993 ◽  
Vol 8 (10) ◽  
pp. 2600-2607 ◽  
Author(s):  
M. Brunel ◽  
S. Enzo ◽  
M. Jergel ◽  
S. Luby ◽  
E. Majkova ◽  
...  

Tungsten/silicon multilayers with tungsten layers of a thickness of 1–2 nm were prepared by means of electron beam deposition. Their structure and thermal stability under rapid thermal annealing were investigated by a combination of x-ray diffraction techniques and cross-sectional transmission electron microscopy. The crystallization behavior was found to depend on the interdiffusion and mixing at the tungsten/silicon interfaces during deposition as well as during annealing. The as-deposited tungsten/silicon multilayers were amorphous and remained stable after annealing at 250 °C/40 s. Interdiffusion and crystallization occurred after annealing all samples from 500 °C/40 s up to 1000 °C/20 s. By performing the same heat treatment in the tungsten/silicon multilayers, the formation of body-centered cubic W was observed with a layer thickness ratio δW/δsi = 1, whereas tetragonal WSi2 was detected in tungsten/silicon multilayers with a layer thickness ratio of δw/δsi ∼0.25. This dependence of the crystallization products on the layer thickness ratio δw/δsi originates from the different phenomena of interdiffusion and mixing at the tungsten/silicon interfaces. The possible formation of bcc tungsten as a first stage of crystallization of tungsten-silicon amorphous phase, rich in tungsten, is discussed.


2001 ◽  
Vol 670 ◽  
Author(s):  
Hyungsuk Jung ◽  
Hyundoek Yang ◽  
Kiju Im ◽  
Hyunsang Hwang

ABSTRACTThis letter describes a unique process for the preparation of high quality tantalum oxynitride (TaOxNy) with zirconium silicate (ZrSixOy) as an interfacial layer for use in gate dielectric applications. Compared with conventional native silicon oxide and oxynitride as an interfacial layer, tantalum oxynitride (TaOxNy) MOS capacitors using zirconium silicate (ZrSixOy) as an interfacial layer exhibit lower leakage current levels at the same equivalent oxide thickness. We were able to confirm TaOxNy/ZrSixOy stack structure by auger electron spectroscopy (AES) and transmission electron microscope (TEM) analysis. The estimated dielectric constant of TaOxNy and ZrSixOywere approximately 67 and 7, respectively. The zirconium silicate is a promising interfacial layer for future high-k gate dielectric applications.


2004 ◽  
Vol 810 ◽  
Author(s):  
Janadass Shanmugam ◽  
Michael Coviello ◽  
Darshak Udeshi ◽  
Wiley P. Kirk ◽  
Meng Tao Nano

ABSTRACTValence mending of a semiconductor surface, such as the Se-passivated Si(001) surface, improves the chemical and thermal stability of the surface as compared to the bare Si(001) surface. In this paper, we report the suppression of Ni silicide formation between Ni and Si(001) through monolayer passivation of Si(001) by Se. Ni was deposited on both Se-passivated and bare Si(001) surfaces. The samples were annealed at temperatures from 400°C to 700°C. Cross-sectional TEM (Transmission Electron Microscopy) revealed that Ni on bare samples reacted with Si at 400°C and formed silicide, whereas Ni on Se-passivated samples did not react with Si at 500°C. Surface composition analysis by XPS (X-Ray Photoelectron Spectroscopy) showed pure Ni surface on Se-passivated samples annealed at 400°C and 500°C, but silicide surface on bare samples annealed at the same temperatures. Hence, Se passivation suppresses the formation of Ni silicide on the Si(001) surface by over 100°C as compared to the bare Si(001) surface. These results may have important implications in source/drain engineering in sub-100 nm Si CMOS (Complementary Metal Oxide Semiconductor) devices.


1989 ◽  
Vol 159 ◽  
Author(s):  
D.B. Fenner ◽  
D.K. Biegelsen ◽  
B.S. Krusor ◽  
F.A. Ponce ◽  
J.C. Tramontana

ABSTRACTGaAs samples deposited on Si by molecular beam epitaxy (MBE) with a graded thickness of 0–3 nm initially show the presence of a metastable two dimensional (2D) layer containing Ga and As. In the thicker regions of the wedge samples, islands (3D topography) form in the presence of the 2D sea, i.e., Stranski – Krastanov growth. Compositional profiles of these wedges were made with in situ Auger electron spectroscopy (AES) which has allowed the identification of at least four regimes of growth. Lattice images from cross – sectional transmission electron microscopy (XTEM) are consistent with the AES profiles. Substrate temperature during deposition of the films has a strong effect on film topography, as does the beam – flux ratio on film stoichiometry.


1989 ◽  
Vol 146 ◽  
Author(s):  
E.J. Yun ◽  
H.G. Chun ◽  
K. Jung ◽  
D.L. Kwong ◽  
S. Lee

ABSTRACTIn this paper, the interactions of sputter-deposited Ti on SiO2 substrates during rapid thermal annealing in nitrogen at 550°C - 900°C for 10 - 60 s have been systematically studied using X-ray diffraction, Auger electron spectroscopy, transmission electron diffraction, TEM & cross-sectional TEM, and sheet resistance measurements.


1999 ◽  
Vol 564 ◽  
Author(s):  
A. Vijayendran ◽  
M. Danek

AbstractWe evaluated PECVD WNx as a potential copper barrier. Ultrathin (100 Å) PECVD WNx films were deposited utilizing WF6/N2/H2 chemistry. Films with N/W stoichiometries ranging from 0.1 to 1.0 and resistivities between 200 – 1000 μΩ-cm were deposited by varying pressure, deposition temperature, N2 flow, and H2 flow. The thermal stability of the films was evaluated by annealing Si/WNx /Cu stacks for 1 hour at temperatures up to 700°C. Barrier failure was detected by sheet resistance change and surface SIMS. The thermal stability was correlated with N/W ratio and free fluorine content as determined by temperature programmed desorption mass spectroscopy. The tests showed that films with N/W ratios between 0.3 and 0.4 had optimal barrier properties, while fluorine was seen to have a detrimental effect on barrier stability. Moreover, tests showed that the substrate affects fluorine concentration as WNx deposited on silicon dioxide has a higher interfacial fluorine content than WNx on silicon. Thus, fluorine contamination at the WNx /Si02 interface led to poor electrical reliability as measured by leakage current vs. time on MOS capacitors.


1998 ◽  
Vol 535 ◽  
Author(s):  
H. C. Kuo ◽  
C. H. Lin ◽  
B. G. Moser ◽  
H. Hsia ◽  
Z. Tang ◽  
...  

AbstractWe present the studies of the thermal stability of various metal including Au, Ti, Pt, Pd and Pt/Ti/Pt/Au Schottky contacts on strained Ga0.2In0.8P/InP semiconductors. Auger electron spectroscopy (AES) analysis and cross-sectional TEM of the thermally annealed Schottky diode were performed to investigate the failure mechanism. For Pt/Ti/Pt/Au schottky contacts on strained GalnP/InP, no significant change was found for samples annealed up to 350°C. However, a drastic degradation of the barrier height and the ideality factor was observed in samples annealed at 400°C, which may be caused by the interdiffusion and penetration of metals into the semiconductor. Finally InGaAs/InP doped channel heterojunction FET's (DC-HFET's) with a GaInP Schottky barrier enhancement layer (SBEL) were grown and fabricated. The 0.25 μm gate-length devices showed excellent DC and RF performance, with anfi of 117 GHz and an fmax of 168 GHz.


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