摘要:

The atomic force microscope was employed to observed in air the surface atomic structure of InSe, one of III‐VI compound semiconductors with layered structures. Atomic arrangements were observed in bothn‐type andp‐type materials. The observed structures are in good agreement with those expected from bulk crystal structures. The atomic images became less clear by repeating the imaging process. Wide area imaging after the imaging of small area clearly showed that a mound was created at the spot previously imaged.

ISSN:0021-8979    

DOI:10.1063/1.354820

出版商:AIP    

年代:1993

数据来源: AIP

摘要:

The time depending influence of HF‐H2O2mixtures on the Si(100) and Si(111) surface was studied by means of x‐ray photoelectron spectroscopy and high resolution electron energy loss spectroscopy (HREELS). The H2O2concentration was varied in the range between 0% and 30%, for the HF concentration 0.5% was used. The oxygen coverage of the silicon surface increases with H2O2concentration which shows up in HREELS spectra as Si–O–Si bridge bonded oxygen and O–H groups. Oxidation of Si–Si backbonds proceeds as can be seen by changes of the Si–H stretching mode. The oxygen uptake of Si(100) with a substantial higher amount of Si–O–Si is faster as compared with Si(111) which reveals Si–OH. Further on we find changes in the morphology of Si(100) surfaces. The dihydride termination decreases with increasing H2O2concentration and immersion time which indicates the formation of Si(111)‐like facets.

ISSN:0021-8979    

DOI:10.1063/1.354821

出版商:AIP    

年代:1993

数据来源: AIP

摘要:

An extensive investigation of InN overlayers on AlN‐buffered (00.1) sapphire by reactive magnetron sputtering has been undertaken and the dependencies of several basic materials properties (film thickness, development and quality of heteroepitaxy, film morphology, and electrical transport) on such key deposition parameters such as the growth temperatures of the insulating AlN buffer layer and the InN overlayer and their thicknesses have been determined. Three prominent effects of the AlN buffer layer are (1) the stabilization of heteroepitaxial growth over a broad range of film and buffer layer growth temperatures; (2) the attainment of a higher Hall mobility (up to 60 cm2/V s) over much of the same range; and, (3) the retention of heteroepitaxial growth, higher Hall mobility, and pseudo‐two‐dimensional growth even in the limit of an InN layer of ∼40 A˚. In the context of a structure‐zone model, the AlN buffer layer is projected to effectively raise the growth temperature of the InN thin film. The increase in effective growth temperature is, however, insufficient to overcome low atomic and cluster mobility and to achieve single‐crystal InN thin film growth.

ISSN:0021-8979    

DOI:10.1063/1.354822

出版商:AIP    

年代:1993

数据来源: AIP

摘要:

The effects of strain energy on the preferred orientation of TiN thin films were investigated. In the TiN film deposited by plasma‐enhanced chemical‐vapor deposition with a power of 50 W, the overall energy of the film mainly depended on the surface energy because its strain energy was relatively small. The preferred orientation of the film corresponded to the plane with the lowest surface energy, i.e., (200). However, in the TiN film deposited by rf sputtering with a power of 200 W, the overall energy of the film was largely controlled by strain energy due to its large strain energy, and its growth orientation corresponded to the plane with the lowest strain energy, i.e., (111). Furthermore, the preferred orientation of the TiN film was changed from (200) to (111) with the film thickness. It is considered that this phenomenon is due to the increase of strain energy with its thickness.

ISSN:0021-8979    

DOI:10.1063/1.355297

出版商:AIP    

年代:1993

数据来源: AIP

摘要:

Elemental materials that condense on surfaces near effusion cells can be reevaporated toward substrates when heated by radiation from effusion furnaces. There they accumulate as unwanted impurities at interfaces and distribute throughout epitaxial films during growth. This effect is greatly increased when shutters are closed. Re‐evaporated aluminum is shown to degrade minority‐carrier properties of Al0.3Ga0.7As/GaAs double heterostructures. Modified temperature schedules and hardware to reduce re‐evaporation effects are suggested.

ISSN:0021-8979    

DOI:10.1063/1.354823

出版商:AIP    

年代:1993

数据来源: AIP

摘要:

Formation of CoSi2films by the reaction of ternary Co/Ti/Si system has been investigated. Ti and Co films were sequentially deposited on Si substrates by ion beam sputtering. It succeeded in the growth of epitaxial single‐crystalline CoSi2films on both Si(111) and Si(100) substrates through a multistep annealing process with temperatures from 550 to 900 °C in a nitrogen environment. A thin layer of TiN was formed on top of the epitaxial CoSi2. The values of Rutherford backscattering spectrometry/channeling minimum yield &khgr;minfor the epitaxial CoSi2films were in the range of 10%–14%. The epitaxial CoSi2grown on Si(111) was found to be composed of typeB.

ISSN:0021-8979    

DOI:10.1063/1.354824

出版商:AIP    

年代:1993

数据来源: AIP

摘要:

The results of Monte Carlo simulation of phase separation during binary film coevaporation are presented for a range of deposition conditions. The model employed assumes that phase separation occurs through surface interdiffusion during deposition, while the bulk of the film remains frozen. Simulations were performed on A‐B alloy films having compositions of 10 and 50 vol % solute. For both film compositions, the lateral scale of the domains at the film surface evolves to a steady‐state size during deposition. A power‐law dependence of the steady‐state domain size on the inverse deposition rate is obtained. Simulation microstructures at 50 vol % compare favorably with those obtained in a previous experimental study of phase separation during coevaporation of Al‐Ge films of the same composition. Results of simulations performed at 10 vol % are compared with the predictions of a theoretical model based on the above assumptions. The power‐law exponent obtained from simulations at 10 vol % is different than that predicted by the theoretical model. The reasons for this difference are discussed.

ISSN:0021-8979    

DOI:10.1063/1.354825

出版商:AIP    

年代:1993

数据来源: AIP

摘要:

A method based on the bending beam technique has been developed to measure the thermal stresses of fine lines confined by a dielectric layer. This method has been employed to determine the thermal stress of Al (2 at. % Cu) lines passivated by a SiO2overlayer between room temperature and 400 °C. The effect of quartz confinement was analyzed by matching the thermal displacement at the metal/passivation interfaces and by imposing a mechanical equilibrium condition on the structure. The analysis enables us to deduce the triaxial stress components of metal and passivation from measurements of the substrate bending parallel and perpendicular to the length direction of the lines. Results of the measurements show a substantial stress enhancement as a result of the confinement, with the stress level significantly higher than that of a passivated blanket film. Parameters that influence the magnitude of the stress components are line geometry, layer deposition conditions, and the extent of plastic deformation during thermal cycling. Results of the measurements are consistent with those determined using x‐ray techniques.

ISSN:0021-8979    

DOI:10.1063/1.354826

出版商:AIP    

年代:1993

数据来源: AIP

摘要:

The bending beam technique and stress analysis developed for stress measurements of fine line structures have been applied to investigate stress relaxation in confined Al (2 at. % Cu) line structures on a Si substrate. The observed relaxation of the line structure is compared with corresponding unpassivated and passivated layered film structures. The overall behavior of all structure is similar, showing an initial plastic deformation, then a fast relaxation in sequence with a log(time) slow relaxation. The kinetics of these relaxation processes are found to decrease due to the presence of the passivation and a higher degree of dielectric layer confinement. In addition, the relaxation behavior of the principal stress components of the line structure is anisotropic and does not vary monotonically with the annealing temperature. The results are attributed to the relaxation mechanism and interaction at the metal/dielectric interface.

ISSN:0021-8979    

DOI:10.1063/1.355327

出版商:AIP    

年代:1993

数据来源: AIP

摘要:

Thick (∼3 &mgr;m) films of InxGa1−xAs grown on GaAs(100) substrates, across the whole composition range, have been examined by transmission electron microscopy and double‐crystal x‐ray diffraction. The results were compared with the observed growth mode of the material determined byinsitureflection high‐energy electron diffraction in the molecular beam epitaxy growth system. The quality of the material degraded noticeably for compositions up tox∼0.5 associated with an increased density of dislocations and stacking faults. In contrast, improvements in quality asxapproached 1.0 were correlated with the introduction of an increasingly more regular array of edge dislocations.  

ISSN:0021-8979    

DOI:10.1063/1.354827

出版商:AIP    

年代:1993

数据来源: AIP