共查询到20条相似文献,搜索用时 31 毫秒
1.
M. Röwekamp A. Goehlich H. F. Döbele 《Applied Physics A: Materials Science & Processing》1992,54(1):61-67
Measurements of velocity distributions of C, B, and Si atoms released in sputtering processes from graphite and carbide targets bombarded with noble gas ions in the 1 keV range are described. Laser-induced fluorescence spectroscopy in the VUV is applied. The VUV radiation necessary to excite the sputtered atoms is provided by stimulated anti-Stokes Raman scattering (SARS) in H2. Surface binding energies are derived from measured velocity distributions; concentrations of sputtered particles, fluxes and sputtering yields are determined. 相似文献
2.
M. I. Guseva V. M. Gureev B. N. Kolbasov S. N. Korshunov Yu. V. Martynenko V. B. Petrov B. I. Khripunov 《JETP Letters》2003,77(7):362-365
The sputtering of tungsten from a target at a temperature of 1470 K during irradiation by 5-eV deuterium ions in a steady-state dense plasma is discovered. The literature values of the threshold for the sputtering of tungsten by deuterium ions are 160–200 eV. The tungsten sputtering coefficient measured by the loss of weight is found to be 1.5×10?4 atom/ion at a deuterium ion energy of 5 eV. Previously, such a sputtering coefficient was usually observed at energies of 250 eV. The sputtering is accompanied by a change in the target surface relief, i.e., by the etching of the grain boundaries and the formation of a wavy structure on the tungsten surface. The subthreshold sputtering at a high temperature is explained by the possible sputtering of adsorbed tungsten atoms that are released from the traps around the interstitial atoms and come to the target surface from the space between the grains. The wavy structure on the surface results from the merging of adsorbed atoms into ordered clusters. 相似文献
3.
H. Oechsner 《Applied Physics A: Materials Science & Processing》1975,8(3):185-198
After a brief outline of the present sputtering theory for a random solid, recent results of the sputtering yieldS for polycrystalline targets are discussed, in particular in view of the influence of the projectile mass and the bombarding angle. The angle dependence ofS at low bombarding energies, and results on the angular distribution of sputtered particles for oblique ion incidence point out necessary modifications of present sputtering theories with respect to the anisotropy of the collision cascades in the solid and the influence of the target surface. The energy distribution of the neutral particles ejected along the target normals is related to the theoretically predictedE ?2-distribution of low energy recoils in the Recent mass spectrometric studies of postionized sputtered neutrals are discussed in view of the formation of sputtered molecules and the application of sputtered neutral mass spectroscopy for surface analysis. Finally, the paper deals with ion-induced surface effects on non-elementary sputtering targets, and the protracted removal of foreign atoms from a matrix. 相似文献
4.
Sputtering of Cu single-crystal, polycrystal and amorphous targets by 5 keV Ar ions has been studied by the binary collision
lattice simulation code Cosipo. The sputtering yields, angular distributions, energy distributions and the space distributions
of the original positions of the sputtered Cu atoms have been calculated. The results are discussed within the framework of
cascade generations and surface structure. 相似文献
5.
采用分子动力学模拟方法研究了样品温度对Ar+与SiC样品表面相互作用的影响。由模拟结果可知,SiC样品中Si原子的溅射产额随着温度的升高而增加,而温度对C原子的溅射产额影响不大。在相同温度下,Si原子的溅射产额要高于C原子的溅射产额。溅射出来的Si原子和C原子主要来源于样品的表层区域,样品中的Si和C原子密度、键密度及它们的成键方式也发生了较大的变化。初始样品中Si和C原子的密度是均匀的,而被轰击过后的样品表面Si原子的密度要高于C原子,而样品中部C原子的密度要高于Si原子。初始样品都是Si-C键,成键方式为Si-Csp3;被轰击过后又有Si-Si和C-C键,成键方式也发生了变化,还有Si-Csp1和Si-Csp2。 相似文献
6.
K. Rödelsperger W. Krüger A. Scharmann 《Zeitschrift für Physik A Hadrons and Nuclei》1975,272(1):127-130
Angular distributions of atoms sputtered with fast ions from smooth amorphous targets are estimated by a straightforward treatment of the collision cascade. When the geometrical situation at oblique ion impact is considered, the angle of maximum emission and the sputtering yield in dependence on the angle of ion incidence are described. 相似文献
7.
Ultraviolet photoelectron spectra show that even at the threshold of detectability, Pd, Ni, and Cu atoms deposited on the basal plane of cleaved graphite nucleate into clusters sufficiently large to exhibit valence band and core binding energies characteristics of bulk metals. However at very low coverage of these metals on amorphous carbon, the spectra show that the valence d-bands have decreased widths and larger binding energies than the bulk metals. Core binding energies show a similar increase at very low coverage. These effects occur because at low coverage on amorphous carbon these metals are present as isolated adatoms. 相似文献
8.
The sputtering of clusters consisting of 13, 27, and 75 copper atoms from the (0001) graphite surface under bombardment by
Cu2 dimers with energies of 100, 200, and 400 eV has been simulated using the molecular dynamics method. A comparative analysis
of the distributions of backscattered particles and their energies over polar angles and the energy distributions of sputtered
atoms has been performed. The factors responsible for the large sputtering yield from surface clusters under their bombardment
with dimers as compared to copper and xenon monomers have been discussed. It has been demonstrated that, in the case of bombardment
with dimers, the substantial role in the sputtering of surface clusters is played by the overlap of collision cascades initiated
by each atom of the incident dimer. The differences in the sputtering under cluster and atom bombardments are especially pronounced
in the case of large surface clusters. 相似文献
9.
以GaP为靶材采用射频磁控溅射法制备GaP红外光学薄膜,通过保持Ar Ⅰ 750nm发射光谱线强度不变获得了不同工艺参数,并对沉积过程进行了计算机模拟.功率较小、气压较大时,Ga和P的溅射率、输运效率及沉积到衬底时的能量均较小,Ga的溅射率及输运效率均大于P的,使薄膜沉积速率较低、薄膜中Ga的含量大于P的,GaP薄膜产生较大吸收.功率较大、气压较小时,Ga和P的溅射率、输运效率及沉积到衬底时的能量均增大,Ga的溅射率大于P的、但其输运效率小于P的,使GaP薄膜的沉积速率增大、薄膜中Ga与P的含量接近化学计量比,GaP薄膜的吸收降低,因此有利于制备厚度较大的GaP薄膜.
关键词:
GaP
薄膜
射频磁控溅射
计算机模拟 相似文献
10.
M. Szymoński 《Applied Physics A: Materials Science & Processing》1980,23(1):89-92
The energy distributions of Cu and Zn atoms sputtered from elements and CuxZn1-x alloys (x=0.80, 0.24) with a 6 keV Ar+ beam have been measured. It was found that the collision-cascade theory properly described the flux of sputtered atoms. From
the spectra the binding energies of Cu and Zn atoms in the elemental and alloy surfaces were determined. The collision-cascade
theory and the experimentally adjusted values of the binding energies allowed for calculation of the total and partial sputtering
yields, and the equilibrium surface composition of the ion bombarded alloys.
This work was carried out as a part of Research Project M.R. I/5. 相似文献
11.
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13.
采用磁控溅射技术在Si衬底上以350?C沉积14 nm的非晶Ge薄膜,通过退火改变系统生长热能,实现了低维Ge/Si点的生长.利用原子力显微镜(AFM)和拉曼(Raman)光谱所获得的形貌和声子振动信息,对Ge点的形成机理和演变规律进行了研究.实验结果表明:在675?C退火30 min后,非晶Ge薄膜转变为密度高达8.5×109cm-2的Ge点.通过Ostwald熟化理论、表面扩散模型和对激活能的计算,很好地解释了退火过程中,Ge原子在Si表面迁移、最终形成纳米点的行为.研究结果表明用高速沉积磁控溅射配合热退火制备Ge/Si纳米点的方法,可为自组织量子点生长实验提供一定的理论支撑. 相似文献
14.
通过分子动力学模拟了入射能量对H原子与晶Si表面相互作用的影响. 通过模拟数据与实验数据的比较, 得到H原子吸附率随入射量的增加 呈先增加后趋于平衡的趋势. 沉积的H原子在Si表面形成一层氢化非晶硅薄膜, 刻蚀产物(H2, SiH2, SiH3和SiH4)对H原子吸附率趋于平衡有重要影响, 并且也决定了样品的表面粗糙度. 当入射能量为1 eV时, 样品表面粗糙度最小. 随着入射能量的增加, 氢化非晶硅薄膜中各成分(SiH, SiH2, SiH3)的量以及分布均有所变化.
关键词:
分子动力学
吸附率
表面粗糙度
氢化非晶硅薄膜 相似文献
15.
K. Rödelsperger W. Krüger A. Scharmann 《Zeitschrift für Physik A Hadrons and Nuclei》1974,269(1):83-88
Measurements of the angular distribution of copper atoms which are sputtered by noble gas ions within the energy range between 0.1 and 1 MeV have been carried out for different angles of ion incidence. The hemisphere over the target surface could be studied with a microphotometer inside the sputtering chamber and the distributions can be plotted in tri-dimensional diagrams. The results are in principle similar to those obtained at lower energies. The angle of maximum emission varies with ion energy and with the angle of incidence and can be related to the sputtering yield. 相似文献
16.
This paper presents a zero order approximation of ion collection during sputtering. Neglecting diffusion, range shortening and knock-on effects and assuming a constant sputtering yield general analytical results are developed which allow a comparison with experimental data. The accumulation of implantation profiles and the build-up of surface concentrations and collected quantities are described in detail for Gaussian range distributions. A thorough discussion of available experimental results indicates that the model is suitable for a variety of projectile-target combinations, in particular for medium mass noble gas atoms collected in high melting point targets. Application to sputtering experiments presents further evidence of a strong fluence dependence of the silicon sputtering yield. Some comments are devoted to recently reported analytical and numerical treatments of ion collection during sputtering. 相似文献
17.
An original experimental method is developed for determining the sputtering coefficients of electrically conducting materials
during bombardment by light gas ions at threshold energies. This information is very valuable in both purely scientific and
practical terms. The basis of the method is a special field-ion-microscopic analysis regime. The procedure for measuring the
sputtering coefficients includes cleaning the surface by field desorption and evaporation, with the subsequent work on an
atomically clean and atomically smooth surface. The method permits identification of single vacancies on the irradiated surface,
i.e., it is possible to count individual sputtered atoms. The method is tested on commercially pure tungsten, tungsten oxide,
and a W-C mixed layer on tungsten under deuterium ion bombardment. The energy dependences of the sputtering coefficients of
these materials for sputtering by deuterium ions at energies of 10–500 eV are obtained and analyzed. An important relationship
between the energy threshold for sputtering and the conditions for oxidation of tungsten is found. The energy threshold for
sputtering of an oxidized tungsten surface is 65 eV. The energy threshold for sputtering of the W-C mixed layer is almost
equal to the corresponding value for pure tungsten.
Zh. Tekh. Fiz. 69, 137–142 (September 1999) 相似文献
18.
D. Cheng I.S. Atanasov M. Hou 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2011,64(1):37-44
The question of the influence of the environment on the structure and thermodynamic state
of a bimetallic cluster is examined, using Metropolis Monte Carlo methods. An embedded
atom model is used to estimate metal energies. The environment is modeled at a generic
level as a rigid matrix which atoms interact with the atoms of an embedded Au-Pd
cuboctahedral cluster via a Lennard Jones (LJ) potential. The high sensitivity of the
cluster properties on its environment is demonstrated by scaling the LJ potential. It is
found that the strength of the interfacial interactions completely determines surface
segregation. Full segregation with either Au or Pd at the surface favors the occurrence of
stable alloy phases in the cluster core while the subsurface layer acts as a buffer
accommodating both the induced surface segregation and the inner composition constrained
by phase stability. Cluster surface disorder induced by an amorphous matrix limits
interface segregation and phase stability in the cluster core, even when the interfacial
interaction strength is weak. The contrast between the epitaxial and amorphous matrix
cases over a wide range of interface energies suggests the importance in the thermodynamic
properties of the cluster core of the interfacial atomic arrangement in the matrix. 相似文献
19.
Sputtering studies with the Monte Carlo Program TRIM.SP 总被引:2,自引:0,他引:2
The Monte Carlo Program TRIM.SP (sputtering version of TRIM) was used to determine sputtering yields and energy and angular distributions of sputtered particles in physical (collisional) sputtering processes. The output is set up to distinguish between the contributions of primary and secondary knock-on atoms as caused by in- and outgoing incident ions, in order to get a better understanding of the sputtering mechanisms and to check on previous theoretical models. The influence of the interatomic potential and the inelastic energy loss model as well as the surface binding energy on the sputtering yield is investigated. Further results are sputtering yields versus incident energy and angle as well as total angular distributions of sputtered particles and energy distributions in specific solid angles for non-normal incidence. The calculated data are compared with experimental results as far as possible. From this comparison it turns out that the TRIM.SP is able to reproduce experimental results even in very special details of angular and energy distributions. 相似文献
20.
Sputter deposition is a complex process; it is obvious that the energy and direction of the particles arriving at the substrate is in close relation with the transport process from the target to the substrate, it is desirable to model this transport of atoms through the background gas. The transport of sputtered Ag atoms during sputter deposition through the gas phase in the facing targets sputtering system studied by Monte Carlo simulation is presented. The model calculates the flux of the atoms arriving at the substrate, their energy, direction and number of collisions they underwent. The dependence of the deposition rates of Ag atoms on the gas pressure and the distance between the targets and substrate were investigated. 相似文献