Implant isolation of ZnO epitaxial layers

2002 ◽  
Vol 744 ◽  
Author(s):  
S. O. Kucheyev ◽  
C. Jagadish ◽  
J. S. Williams ◽  
P. N. K. Deenapanray ◽  
Mitsuaki Yano ◽  
...  

ABSTRACTThe formation of highly resistive films of single-crystal ZnO as a result of irradiation with MeV Li, O, and Si ions is demonstrated. Results show that the ion doses necessary for electrical isolation close-to-inversely depend on the number of ion-beam-generated atomic displacements. Results show that an increase in the dose of 2 MeV O ions (up to ∼ 2 orders of magnitude above the threshold isolation dose) and irradiation temperature (up to 350 °C) has a relatively minor effect on the thermal stability of electrical isolation, which is limited to temperatures of ∼ 300 — 400 °C. For the case of multiple-energy implantation with keV Cr, Fe, or Ni ions, the evolution of sheet resistance with annealing temperature is consistent with defect-induced isolation, with a relatively minor effect of Cr, Fe, or Ni impurities on the thermal stability of isolation. Based on these results, the mechanism for electrical isolation in ZnO by ion bombardment is discussed.

1995 ◽  
Vol 391 ◽  
Author(s):  
Dan-Xia Xu ◽  
Suhit R. Das ◽  
Lynden Erickson ◽  
Abdalla Naem

AbstractThe properties of platinum silicide have been evaluated in the form of blanket films and confined lines with linewidth down to 0.15 μm. Pt films, ranging in thickness from 150Å to 1000Å, were prepared by sputter-deposition onto Si (100) blanket substrates or substrates patterned with windows of various sizes in SiO2. The samples were then annealed in a rapid thermal annealing system up to 550°C to form PtSi. The sheet resistance of silicide lines did not change significantly with linewidth. The thermal stability of the sheet resistance of PtSi was also measured for different linewidths and film thicknesses. The sheet resistance remained stable on annealing up to 850°C for a silicide film made of 250Å Pt and did not appear to be sensitive to the linewidth. The thickness dependence of the thermal stability of resistance was also evaluated.The stress of the silicide films was measured using a laser deflection system. The asdeposited metal films were under compressive stress, but the stress turned into tensile upon annealing when silicide started to form. After PtSi was formed, the stress remained stable with annealing temperature until approximately 900°C when the stress exhibited a sharp decrease. Unlike electrical conductance, however, the breakdown temperature for stress did not strongly depend on the film thickness.


2004 ◽  
Vol 812 ◽  
Author(s):  
L. Gao ◽  
J. Gstöttner ◽  
R. Emling ◽  
Ch. Linsmeier ◽  
M. Balden ◽  
...  

AbstractThe physical and electrical properties as well as thermal stability of reactively sputtered titanium nitride (TiN) film serving as a diffusion barrier was studied for silver (Ag) metallization. The thermal stability of Ag/TiN metallizations on Si with 12-nm-thick TiN barriers, as-deposited and after annealing at 300-650°C in N2/H2 for 30 min, was investigated with sheet resistance measurement, X-ray diffraction, focused ion beam-scanning electron microscopy, atomic force microscopy and X-ray photoelectron spectroscopy. According to electrical measurement no change of sheet resistance was found after annealing at 600°C, but an abrupt rise appeared at 650°C annealing. There are two causes by which the Ag/TiN/Si structure became degraded. One is agglomeration of the silver layer, and the other is oxidation and diffusion which are also associated problems during thermal annealing.


1998 ◽  
Vol 514 ◽  
Author(s):  
M. F. Wu ◽  
A. Vantomne ◽  
S. Hogg ◽  
H. Pattyn ◽  
G. Langouche ◽  
...  

ABSTRACTThe Nd-disilicide, which exists only in a tetragonal or an orthorhombic structure, cannot be grown epitaxially on a Si(111) substrate. However, by adding Y and using channeled ion beam synthesis, hexagonal Nd0.32Y0.68Si1.7 epilayers with lattice constant of aepi = 0.3915 nm and cepi = 0.4152 nm and with good crystalline quality (χmin of Nd and Y is 3.5% and 4.3 % respectively) are formed in a Si(111) substrate. This shows that the addition of Y to the Nd-Si system forces the latter into a hexagonal structure. The epilayer is stable up to 950 °C; annealing at 1000 °C results in partial transformation into other phases. The formation, the structure and the thermal stability of this ternary silicide have been studied using Rutherford backscattering/channeling, x-ray diffraction and transmission electron microscopy.


1993 ◽  
Vol 73 (11) ◽  
pp. 7969-7971 ◽  
Author(s):  
Qixin Guo ◽  
Osamu Kato ◽  
Akira Yoshida

2021 ◽  
Vol 1016 ◽  
pp. 338-344
Author(s):  
Wan Ji Chen ◽  
Jie Xu ◽  
De Tong Liu ◽  
De Bin Shan ◽  
Bin Guo ◽  
...  

High-pressure torsion (HPT) was conducted under 6.0 GPa on commercial purity titanium up to 10 turns. An ultrafine-grained (UFG) pure Ti with an average grain size of ~96 nm was obtained. The thermal properties of these samples were studied by using differential scanning calorimeter (DSC) which allowed the quantitative determination of the evolution of stored energy, the recrystallization temperatures, the activation energy involved in the recrystallization of the material and the evolution of the recrystallized fraction with temperature. The results show that the stored energy increases, beyond which the stored energy seems to level off to a saturated value with increase of HPT up to 5 turns. An average activation energy of about 101 kJ/mol for the recrystallization of 5 turns samples was determined. Also, the thermal stability of the grains of the 5 turns samples with subsequent heat treatments were investigated by microstructural analysis and Vickers microhardness measurements. It is shown that the average grain size remains below 246 nm when the annealing temperature is below 500 °C, and the size of the grains increases significantly for samples at the annealing temperature of 600 °C.


2020 ◽  
Vol 46 (7) ◽  
pp. 9192-9197 ◽  
Author(s):  
Liaoyuan Zhang ◽  
Wenping Geng ◽  
Xi Chen ◽  
Yimeng Li ◽  
Xiaojun Qiao ◽  
...  

2003 ◽  
Vol 777 ◽  
Author(s):  
B.J. Inkson ◽  
G. Dehm

AbstractPt nanowires have been produced by FIB deposition of Pt thin films in a commercial Ga+ focused ion beam (FIB) system, followed by cross-sectional sputtering to form electron transparent Pt nanowires. The thermal stability of amorphous FIB manufactured Pt wires has been investigated by in-situ thermal cycling in a TEM. The Pt wires are stable up to 580-650°C where partial crystallization is observed in vacuum. Facetted nanoparticles grow on the wire surface, growing into free space by surface diffusion and minimising contact area with the underlying wire. The particles are fcc Pt with some dissolved Ga. Continued heating results in particle spheroidization, coalescence and growth, retaining the fcc structure.


2017 ◽  
Vol 62 ◽  
pp. 192-195 ◽  
Author(s):  
Tuan T. Tran ◽  
Hemi H. Gandhi ◽  
David Pastor ◽  
Michael J. Aziz ◽  
J.S. Williams

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