Growth and Structure of Metallic Barrier Layer and Interconnect Films I: Exeriments

1999 ◽  
Vol 562 ◽  
Author(s):  
D. L. Windt ◽  
J. Dalla Tortre ◽  
G. H. Gilmer ◽  
J. Sapjeta ◽  
R. Kalyanaraman ◽  
...  

ABSTRACTWe present experimental results directed at understanding the growth and structure of metallic barrier layer and interconnect films. Numerical simulation results associated with this experimental work are presented in an accompanying paper in these proceedings. Here, thin films of Al, Ti, Cu and Ta have been grown by magnetron sputtering onto oxidized Si substrates. Using a specially-constructed substrate holder, the orientation of the substrate with respect to the growth direction was varied from horizontal to vertical. Films were grown at both low and high argon pressure; in the case of Ta, the cathode power was varied as well. The film structure and in particular the surface roughness was measured by X-ray reflectance and also by atomic force microscopy. We find that the surface roughness increases markedly with orientation angle in the case of Ta and Cu films, and in Ti films grown at high argon pressure. At low pressure, however, the Ti film surface roughness remains constant for all substrate orientations. No variation in roughness with either orientation angle or argon pressure was observed in the Al films. These results suggest that, under certain circumstances, shadowing effects and/or grain orientation (i.e., texture) competition during growth can give rise to lower density, more porous (and thus more rough) films, particularly at large orientation angles, as on sidewalls in sub-micron trenches.

1999 ◽  
Vol 564 ◽  
Author(s):  
D. L. Windt ◽  
J. Dalla Torre ◽  
G. H. Gilmer ◽  
J. Sapjeta ◽  
R. Kalyanaraman ◽  
...  

AbstractWe present experimental results directed at understanding the growth and structure of metallic barrier layer and interconnect films. Numerical simulation results associated with this experimental work are presented in an accompanying paper in these proceedings. Here, thin films of Al, Ti, Cu and Ta have been grown by magnetron sputtering onto oxidized Si substrates. Using a specially-constructed substrate holder, the orientation of the substrate with respect to the growth direction was varied from horizontal to vertical. Films were grown at both low and high argon pressure; in the case of Ta, the cathode power was varied as well. The film structure and in particular the surface roughness was measured by X-ray reflectance and also by atomic force microscopy. We find that the surface roughness increases markedly with orientation angle in the case of Ta and Cu films, and in Ti films grown at high argon pressure. At low pressure, however, the Ti film surface roughness remains constant for all substrate orientations. No variation in roughness with either orientation angle or argon pressure was observed in the Al films. These results suggest that, under certain circumstances, shadowing effects and/or grain orientation (i.e., texture) competition during growth can give rise to lower density, more porous (and thus more rough) films, particularly at large orientation angles, as on sidewalls in sub-micron trenches.


1995 ◽  
Vol 396 ◽  
Author(s):  
Seok-Keun Koh ◽  
Young-Soo Yoon ◽  
Ki-Hwan Kim ◽  
Hong-Gui Jang ◽  
Hyung-Jin Jung

AbstractPartially ionized beam deposition of Cu thin films on glass at room temperature were carried out to fabricate Cu laser mirrors with good structural and reflectance properties. At a constant film thickness of 600 Å, the grain size of as-grown Cu films increased with acceleration voltage, and there was no indication of defects such as cracks and/or large pores in the film surface as shown in scanning electron microscopy images. Root-mean-square(Rms) surface roughnesses of the films with thicknesses of 600 Å were measured by atomic force microscopy. RmS surface roughness increased when acceleration voltage increased from 0 kV to 2 kV, but decreased at the acceleration voltage of 3 kV. RmS surface roughness of the film grown at 4 kV, however, increased again. At the acceleration voltage of 3 kV, reflectance of the films increased with the film thickness until 600 Å and decreased at the film thickness of 800 Å. The reflectance results showed that the Cu film deposited at 3 kV had higher reflectance than that of others. Our results suggest that it is possible to grow the Cu film with good structural and optical properties on glass substrate at room temperature by partially ionized beam deposition.


Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1914
Author(s):  
Rúben F. Santos ◽  
Bruno M. C. Oliveira ◽  
Alexandre Chícharo ◽  
Pedro Alpuim ◽  
Paulo J. Ferreira ◽  
...  

The use of Ta/TaN barrier bilayer systems in electronic applications has been ubiquitous over the last decade. Alternative materials such as Co-W or Ru-W alloys have gathered interest as possible replacements due to their conjugation of favourable electrical properties and barrier layer efficiency at reduced thicknesses while enabling seedless Cu electroplating. The microstructure, morphology, and electrical properties of Cu films directly electrodeposited onto Co-W or Ru-W are important to assess, concomitant with their ability to withstand the electroplating baths/conditions. This work investigates the effects of the current application method and pH value of the electroplating solution on the electrocrystallisation behaviour of Cu deposited onto a Co-W barrier layer. The film structure, morphology, and chemical composition were studied by X-ray diffraction, scanning electron microscopy and atomic force microscopy, as well as photoelectron spectroscopy. The results show that the electrolyte solution at pH 1.8 is incapable of creating a compact Cu film over the Co-W layer in either pulsed or direct-current modes. At higher pH, a continuous film is formed. A mechanism is proposed for the nucleation and growth of Cu on Co-W, where a balance between Cu nucleation, growth, and preferential Co dissolution dictates the substrate area coverage and compactness of the electrodeposited films.


1992 ◽  
Vol 280 ◽  
Author(s):  
H. Rojhantalab ◽  
M. Moinpour ◽  
N. Peter ◽  
M.L.A. Dass ◽  
W. Hough ◽  
...  

ABSTRACTChemically vapor deposited borophosphosilicate glass (BPSG) has been widely used in microelectronic device fabrication as interlayer dielectric film due to its excellent planarization, gettering and flow properties. With device geometry reducing to sub micron levels, there is an increasingly greater emphasis on detection and elimination of sub micron defects particularly on deposited film. In this paper, we report on the evaluation and characterization of the surface roughness of BPSG films of various thicknesses and film compositions deposited on Si substrates using the Atomic Force Microscopy (AFM). The effects of high temperature densification process on the surface roughness are presented. The defect detection capabilities of conventional laser-based particle counters with respect to the surface roughness of BPSG films are investigated.


1994 ◽  
Vol 361 ◽  
Author(s):  
D. K. Fork ◽  
F. Armani-Leplingard ◽  
J. J. Kingston

ABSTRACTOptical losses are a barrier to use of ferroelectric waveguide thin films. Losses of about 2 dB/cm will reduce the efficiency of a frequency doubler by over 50%. Achieving losses on this order in conjunction with other essential film properties is difficult. The optical loss has several origins, including absorption, mode leakage, internal scattering and surface scattering. When the film surface morphology is accurately known, it is possible to estimate the surface scattering component of the loss. We have employed atomic force microscopy and computer modeling to compute, and correlate the optical loss as a function of film thickness and wavelength. The results suggest upper limits to the morphological roughness for various device applications. For lithium niobate films on sapphire which are intended to frequency double into the blue part of the spectrum, the optimal film thickness is about 400 nm and the RMS roughness is constrained below about 1.0 nm, with some weak dependence on grain size. Although present growth techniques do not appear to achieve this level of surface flatness intrinsically, an understanding of the morphological development of the film structure may lead to improvements.


Author(s):  
M. DiBattista ◽  
S. V. Patel ◽  
J. F. Mansfield ◽  
J. L. Gland ◽  
J. W. Schwank

Thin film electronic devices that employ resistance change responses of Pt / Ti films to detect gas species have been microfabricated at the University of Michigan. Atomic force microscopy (AFM) is used to investigate morphology of the Pt / Ti sensing films deposited on the microfabricated device. These Pt / Ti sensing films are strongly influenced by many factors, making it difficult to determine the exact relationship between film structure, chemical sensitivity, and selectivity. In-situ AFM investigations of Pt / Ti films on this device at elevated temperatures provides the opportunity for real time observation of film morphology changes under controlled conditions, testing sensing film stability during device operation, and correlating film structure to resistance.Observation of the Pt / Ti film surface and in-situ resistance measurements at elevated temperatures are possible due to the construction of the sensing device. The sensors are based on chemically active thin films deposited on a micromachined silicon window, supported by a 300 μn thick silicon rim.


2014 ◽  
Vol 21 (06) ◽  
pp. 1450079 ◽  
Author(s):  
LIM YANG ◽  
SHI JIE WANG ◽  
JI CHUAN HUO ◽  
XIAO HONG LI ◽  
JIAN XIN GUO ◽  
...  

Ta (3.3 nm)/ Ni – Al (3.3 nm) integrated films deposited on Si substrates by magnetron sputtering, annealed at various temperatures in a ultra-high vacuum, have been studied as diffusion barrier layers between Cu and Si for application in Cu interconnection. The images of transmission electron microscopy (TEM) prove that the cross-sectional interfaces of Cu / Ta / Ni – Al / Si sample annealed at 600°C are clear and sharp. No Cu –silicide peaks can be found from the X-ray diffraction (XRD) patterns of the 850°C annealed sample, but the sheet resistance of the sample increases abruptly. Moreover, large grooves are found from the image of atomic force microscopy (AFM) for the 850°C annealed sample, implying the failure of the diffusion barrier. The integrated Ta / Ni – Al barrier layer retains thermally stable nature up to at least 800°C, indicating that the Ta / Ni – Al integrated film is an excellent diffusion barrier between Cu and Si .


1994 ◽  
Vol 361 ◽  
Author(s):  
Scott R. Summerfelt ◽  
Dave Kotecki ◽  
Angus Kingon ◽  
H.N. Al-Shareef

ABSTRACTThe formation of Pt hillocks during high temperature processing is a problem when using Pt as a bottom electrode for high dielectric constant materials. The hillock height is frequently larger than the dielectric thickness, degrading the leakage current of the device. In this work, Pt was deposited by electron beam evaporation on in-situ formed 40 nm ZrO2 coated SiO2 / Si substrates. The samples were then annealed at temperatures between 400°C and 700°C for times ranging from 2 min to 40 min. The surface roughness was measured by atomic force microscopy (AFM). The surface was characterized using Ra, RMS and Zmax over 5 μm × 5μm regions. Zmax is sensitive to hillock formation and Ra is sensitive to changes in general surface roughness. Analysis of Zmax indicates that 100 nm Pt / ZrO2 deposited at 315°C forms hillocks above 450°C during initial heatup. Subsequently, the hillocks decay for temperatures of 600°C and above such that they are almost gone after a 30 min air anneal. In-situ wafer stress measurements of Pt / ZrO2 were performed in O2 at temperatures up to 650°C. The Pt relaxes above 500°C in O2.


Coatings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 117
Author(s):  
Alexander Rogozhin ◽  
Andrey Miakonkikh ◽  
Elizaveta Smirnova ◽  
Andrey Lomov ◽  
Sergey Simakin ◽  
...  

Ruthenium thin films were deposited by plasma-enhanced atomic layer deposition (PEALD) technology using Ru(EtCp)2 and oxygen plasma on the modified surface of silicon and SiO2/Si substrates. The crystal structure, chemical composition, and morphology of films were characterized by grazing incidence XRD (GXRD), secondary ion mass spectrometry (SIMS), and atomic force microscopy (AFM) techniques, respectively. It was found that the mechanism of film growth depends crucially on the substrate temperature. The GXRD and SIMS analysis show that at substrate temperature T = 375 °C, an abrupt change in surface reaction mechanisms occurs, leading to the changing in film composition from RuO2 at low temperatures to pure Ru film at higher temperatures. It was confirmed by electrical resistivity measurements for Ru-based films. Mechanical stress in the films was also analyzed, and it was suggested that this factor increases the surface roughness of growing Ru films. The lowest surface roughness ~1.5 nm was achieved with a film thickness of 29 nm using SiO2/Si-substrate for deposition at 375 °C. The measured resistivity of Ru film is 18–19 µOhm·cm (as deposited).


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