A novel copper damascene technique for power loaded SAW structures

2004 ◽  
Vol 833 ◽  
Author(s):  
S. B. Menzel ◽  
M. Albert ◽  
D. Reitz ◽  
H. Wendrock ◽  
H. Schmidt ◽  
...  

ABSTRACTThe damage of finger electrodes of surface acoustic wave (SAW) structures due to material transport (acoustomigration) forming voids and hillocks is strongly associated with the SAW stress field, the temperature and properties of the fingers material and their configuration. By application of Cu thin films a significant higher performance of SAW structures with respect to power durability, reliability and lifetime is obtained. In the present paper Cu finger electrodes of a special power SAW test structure were fabricated in trenches of STX quartz substrates using the copper damascene technique. In comparison with conventional finger electrodes located on the substrate surface, such an embedded structure enables some new features regarding their acoustical and acoustomigration behavior. So high power SAW load cannot cause fatal failures by shorts between adjacent fingers. This fact is specially important for SAW devices in the GHz range. The trench structuring into the substrate was carried out by reactive ion (RIE) or ion beam etching (IBE) technique using a metallic hard mask. Etched trenches were filled with a conductive Ta-Si-N / Cu-layer system by magnetron sputtering in a cluster tool, and structured by a chemical-mechanical polishing (CMP) process. Subsequently, after cleaning an insulating Ta-based barrier (system Ta-Si-O / Ta-Si-N) layer was deposited on the wafer surface. This covering layer also acts as a protective coating. Such a metallization system enables sufficient bonding properties using Al-wires. First results of electrical measurements show that travelling SAW could be excited in quartz substrates.

Author(s):  
С.А. Шарко ◽  
А.И. Серокурова ◽  
Н.Н. Новицкий ◽  
А.И. Стогний ◽  
В.А. Кецко

Gold films with a thickness of several tens of nanometers were obtained on silicon and quartz substrates by ion-beam deposition – sputtering. It is shown that the predominant lateral growth of nanoscale metal layers along the substrate surface occurs under exposure to the high-energy component of the sputtered atoms flux. The decisive role in the nanometer gold film for-mation is played by the elastic collision of sputtered metal atoms with atoms of the substrate and the growing film. The application of the manifold deposition – sputtering operation allows sup-pressing the grain formation process and obtaining gold films with better characteristics than those with a single deposition.


2018 ◽  
Vol 2018 ◽  
pp. 1-7
Author(s):  
Ching-Hsiu Chen ◽  
Assamen Ayalew Ejigu ◽  
Liang-Chiun Chao

Cu2O has been deposited on quartz substrates by reactive ion beam sputter deposition. Experimental results show that by controlling argon/oxygen flow rates, both n-type and p-type Cu2O samples can be achieved. The bandgap of n-type and p-type Cu2O were found to be 2.3 and 2.5 eV, respectively. The variable temperature photoluminescence study shows that the n-type conductivity is due to the presence of oxygen vacancy defects. Both samples show stable photocurrent response that photocurrent change of both samples after 1,000 seconds of operation is less than 5%. Carrier densities were found to be 1.90 × 1018 and 2.24 × 1016 cm−3 for n-type and p-type Cu2O, respectively. Fermi energies have been calculated, and simplified band structures are constructed. Our results show that Cu2O is a plausible candidate for both photoanodic and photocathodic electrode materials in photoelectrochemical application.


2002 ◽  
Vol 20 (3) ◽  
pp. 435-440 ◽  
Author(s):  
P.A. SEIDL ◽  
D. BACA ◽  
F.M. BIENIOSEK ◽  
A. FALTENS ◽  
S.M. LUND ◽  
...  

The High Current Experiment (HCX) is being assembled at Lawrence Berkeley National Laboratory as part of the U.S. program to explore heavy ion beam transport at a scale representative of the low-energy end of an induction linac driver for fusion energy production. The primary mission of this experiment is to investigate aperture fill factors acceptable for the transport of space-charge dominated heavy ion beams at high space-charge intensity (line-charge density ∼ 0.2 μC/m) over long pulse durations (>4 μs). This machine will test transport issues at a driver-relevant scale resulting from nonlinear space-charge effects and collective modes, beam centroid alignment and beam steering, matching, image charges, halo, lost-particle induced electron effects, and longitudinal bunch control. We present the first experimental results carried out with the coasting K+ ion beam transported through the first 10 electrostatic transport quadrupoles and associated diagnostics. Later phases of the experiment will include more electrostatic lattice periods to allow more sensitive tests of emittance growth, and also magnetic quadrupoles to explore similar issues in magnetic channels with a full driver scale beam.


2014 ◽  
Vol 85 (2) ◽  
pp. 02B305 ◽  
Author(s):  
U. Fantz ◽  
P. Franzen ◽  
B. Heinemann ◽  
D. Wünderlich

1983 ◽  
Vol 29 ◽  
Author(s):  
Y. Pauleau ◽  
R. Stawski ◽  
Ph. Lami ◽  
G. Auvert

ABSTRACTSilane molecules have been irradiated by a pulsed CO2 laser operating at 10.59 μm. The threshold of silicon formation by homogeneous dissociation of silane has been investigated as a function of laser fluence (0.1–3.5 J/cm2) and silane pressure (1–100 Torr). Silicon films have been deposited on quartz substrates using the laser beam either perpendicular or parallel to the substrate surface. The crystallographic structure and deposition rate of these silicon films are found to be dependent on the incident angle of the laser beam, silane pressure, substrate temperature and laser fluence. The growth mechanism of these films is discussed.


Author(s):  
Xinyue Wang ◽  
Zejun Zeng ◽  
Guoqi Q. Zhang ◽  
Jing Zhang ◽  
Pan Liu

Abstract Recent years, the sintered silver paste was introduced and further developed for power electronics packaging due to low processing temperature and high working temperature. The pressure-less sintering technology reduces the stress damage caused by the pressure to the chip, improves reliability, and is widely applied in manufacturing. Currently, most existed studies are focused on alcohol-based sintered silver pastes while resins have been demonstrated to improve the bonding properties of solder joints. Hence, the performance and sintering mechanisms with epoxy-based silver paste need to be further explored. In this work, a methodology for multi-factor investigation is settled on the epoxy-based silver paste to reveal the relationship between the strength and the different influence factors. We firstly analyzed the characteristics of commercialized epoxy-based silver paste samples, including silver content, silver particle size, organic paste composition, sample viscosity, and thermal conductivity. Samples were then prepared for shear tests and microstructure analysis under different pressure-less sintering temperatures, holding time, substrate surface, and chip size. Full factor analysis results were further discussed in detail for correlation. The influence factors were ranked from strong to weak as follows: sintering temperature, substrate surface, chip size, and holding time. Finally, a thermal cycling test was carried out for reliability analysis. Epoxy residues are one of the possible reasons which result in shear strength decreasing exponentially.


1993 ◽  
Vol 316 ◽  
Author(s):  
E.N. Shauly ◽  
E. Koltin ◽  
I. Munin ◽  
Y. Avrahamov

ABSTRACTIon implantation in semiconductor devices frequently leads to a substantial wafer surface charge build up. Control of this charge during high current implantation is a major process issue, as it may affect the yield and reliability of thin dielectric layers. In addition, the charge build up may affect the ion beam resulting in a non-uniform implant and a reduction in device yield. Control of a specific machine parameter, that will give the charge condition of the ion implanter will enable to neutralize the charge build up.In this study, Disk Current Monitoring (DCM) is shown to be a reliable method for monitoring the Electron Shower (ES) performance in real time. A correlation was found between DCM level and yields, and between DCM level and breakdown voltage, as well as different maintenance activities regarding me ES. A simple 5 steps method is described to achieve a reliable, real time charge monitor, to insure operation within the “High Yield Range”.


1985 ◽  
Vol 45 ◽  
Author(s):  
N. J. Kepler ◽  
N. W. Cheung

ABSTRACTIon-beam mixing and rapid thermal annealing (RTA) techniques are used to form shallow and heavily-doped n+ layers in undoped GaAs. RTA reduces surface degradation and improves crystalline quality compared to lengthy thermal cycles, although furnace annealing producesidentical electrical characteristics. Ion-beam mixing has only a small effect on the diffusion of a deposited GeSe film, because the damage created by implantation is repaired during RTA before significant diffusion occurs. We define a threshold temperature representing the onset of significant electrical activation and/or diffusion, and propose a model relating the annealing, activation, and diffusion temperatures for the GeSe/GaAs system. RBS. SIMS, and electrical measurements show that extremely shallow layers with a sheet resistivity as low as 1480/El can be formed in GaAs by diffusion from a GeSe source. This technique has potential application to the formation of shallow ohmic contacts for GaAs integrated circuits.


Author(s):  
Dedy Ng ◽  
Milind Kulkarni ◽  
Hong Liang

One major concern in post-CMP cleaning is particles contamination on the substrate surface after the CMP process. These particles can be abrasive particles from the slurry, debris from pad material, and particles of film being polished. The cleaning method used in this study is direct contact of the substrate surface and brush sweeping. To enhance the cleaning process, an anionic surfactant is added in the cleaning solution. In order to understand effects of surfactant molecules on post-CMP cleaning, for the first time, we use a tribological approach over a range of surfactant concentration and temperature. In this regard, we observe how the surfactant behavior before and after it reaches the critical micelles concentration (cmc). Experimental results show that increase in surfactant concentration can promote bilayer interaction of micelles on the hydrophilic particles. Based on our study, we propose an interactive explanation of surface molecules with the wafer surface and nanoparticles through friction. This understanding will serve as a guide on how much surfactant should be added in order to achieve effective particle removal.


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