摘要:

Radio frequency (rf) sputtering is used for the deposition and etching of thin layers. In both cases the target etch rate must be controlled, and often power input has been used as one of the controlling parameters. An earlier paper has shown that the applied rf target voltage (Vpp) was a more useful parameter, and here new data is presented which indicates that the peak‐to‐peak voltage remains the preferable parameter for both etch rate control and in transferring between machines. However, a new method is described here which obtains the discharge power by subtracting losses from the total power reading. This discharge power is shown to be related to etch rates, and can thus be used as an aid in the scaling of system sizes. In addition, this discharge power exhibits interesting behavior as the pressure is varied, at constant applied rf voltage. Three main regions are evident when etching Si with CF4: at low pressures directional ion‐induced etching is obtained; in an intermediate region the input power rises rapidly with pressure and the etching is less directional resulting in overhang profiles; and at high pressures an isotropic etching component results in undercut profiles. The two extreme regions correlate with the commonly identified regimes of: (a) low power input, low pressure reactive sputter etching, and (b) high power input, high pressure plasma etching.

ISSN:0734-2101    

DOI:10.1116/1.572218

出版商:American Vacuum Society    

年代:1983

数据来源: AIP

摘要:

An ion beam milling technique is used to planarize the SiO2steps in 8 μm period field‐access magnetic bubble devices. A photoresist coating is first applied over the SiO2steps to produce a smooth surface. The resist layer is then ion milled using conditions that give equal milling rates for the resist and SiO2films. The planar resist surface is thus preserved in SiO2after the resist layer is completely milled away. Magnetic bubble devices fabricated by this process are shown to operate at much lower in‐plane drive field than similar devices fabricated by conventional nonplanar processes.

ISSN:0734-2101    

DOI:10.1116/1.572212

出版商:American Vacuum Society    

年代:1983

数据来源: AIP

摘要:

A relatively new deposition technique involving laser‐assisted evaporation is applied to the deposition of thin ZnO films. Highly oriented and crystalline films of ZnO were obtained by CO2laser evaporation of ZnO powder targets on substrates held at 50–450 °C. Optical transmission spectra of these films show a sharp cutoff at 380 nm. The refractive index, as measured by ellipsometry, is 1.98–2.04. As‐grown films are conducting (0.1–1 Ω cm), but become insulating when 0.1% Li2O is added to the source. SAW devices built with these films proved the piezoelectric nature of laser‐evaporated ZnO. It is found that the laser deposition technique is applicable to producing device quality ZnO films with good reproducibility.

ISSN:0734-2101    

DOI:10.1116/1.572219

出版商:American Vacuum Society    

年代:1983

数据来源: AIP

摘要:

Deposits of aluminum oxides (Al2O3) have been formed by a chemical vapor deposition (CVD) technique involving the application of gas mixtures of AlCl3, CO2, and H2onto TiN coated cemented carbide substrates. The relationships between the deposition rate and various reaction parameters such as the gas flow rate, the deposition temperature, the composition of reactant gases, and the system pressure were studied. The CVD of Al2O3is a thermally activated process and limited by the surface chemical reaction. The apparent activation energy is about 36 kcal/mol at 50 Torr and decreases with the increasing system pressure. The dependence of the deposition rate on the reactant gas composition is affected by the variation of the relative contents of the aluminum donor and the oxygen donor. At a low AlCl3mole fraction, the deposition rate increases with the AlCl3mole fraction; however, at higher AlCl3mole fractions than 1.0×10−2the deposition rate is mainly influenced by the H2O‐forming reaction between CO2and H2.

ISSN:0734-2101    

DOI:10.1116/1.572221

出版商:American Vacuum Society    

年代:1983

数据来源: AIP

摘要:

UV‐stimulated photocurrent spectroscopy and photocurrent transient methods have been used to determine the effects of deposition parameters on the electron trapping level density and its energy distribution in rf‐sputtered Ta2O5films. Results of this investigation indicate that the electron trapping level density can be greatly reduced by depositing the film at a pressure of 2×10−3Torr with an rf‐magnetron sputtering system. Experimental results also indicate the presence of the distribution for traps peaked at 2.7 eV below the conduction band in Ta2O5films sputtered at a pressure of 2×10−3Torr. A first‐order kinetic model was used to compute trapping parameters (trap density and photoionization cross section). The results of this analysis indicate that the density of the 2.7 eV level is on the order of 4×1015cm−3, which is three orders of magnitude lower than that for anodic Ta2O5films, and that the photoionization cross section (at 2.7 eV) is on the order of 10−20cm2.

ISSN:0734-2101    

DOI:10.1116/1.572222

出版商:American Vacuum Society    

年代:1983

数据来源: AIP

摘要:

The initial oxidation of a clean polycrystalline titanium film was studied by Auger electron spectroscopy (AES) and electron energy loss spectroscopy (ELS), while simultaneously monitoring the total oxygen uptake using the quartz crystal microbalance (QCM). Quantitation of the OKLLand TiLMMAES intensities reveals that the surface stoichiometry at the initial stages of oxidation (<100 L O2at 1×10−5Torr) corresponds to that expected for Ti2O3, and the ELS results also suggest the presence of the lower oxidation states of titanium (+2,+3) on the surface. The microgravimetric results indicate that the oxidation is not confined to the region sampled by the electron spectroscopic methods, and a surface layer of Ti2O3whose thickness is ∼40 Å is consistent with the observed combination of results.

ISSN:0734-2101    

DOI:10.1116/1.572223

出版商:American Vacuum Society    

年代:1983

数据来源: AIP

摘要:

It is reported that as‐grown vacuum evaporated thin films of Pb0.8Sn0.2Te werep‐type with low mobility. Annealing of these films in vacuum and under tin pressure resulted in a significant increase in mobility. The mobility of the films annealed in tin for 60 min was about 3.6 ×103cm2/V s.

ISSN:0734-2101    

DOI:10.1116/1.572225

出版商:American Vacuum Society    

年代:1983

数据来源: AIP

摘要:

A method of producing fine‐grained PbInAu thin films reported by Huang and co‐workers has been evaluated for use in Josephson technology integrated circuits. Both junction‐related and nonjunction characteristics of the base electrode layer were considered. It was found necessary to interchange the order of deposition of two of the layers in the vertical structure and to modify the homogenization step in the base electrode process. The fine grain size of the films was found to be due to the presence of a layer of AuIn2precipitates which impede grain growth.

ISSN:0734-2101    

DOI:10.1116/1.572226

出版商:American Vacuum Society    

年代:1983

数据来源: AIP

摘要:

The use of laser annealing in the preparation of a clean, well‐ordered Ni(001) surface has been investigated. The surface was cleaned by argon ion bombardment and subsequently irradiated with the fundamental output of a high power, Q‐switched ruby laser. The laser treated surface was characterized by use of Auger electron spectroscopy and both conventional and spin‐polarized LEED, and the data compared to that from a surface prepared by thermal annealing. Laser irradiation of a sputtered surface at energy densities of ∼0.8 J cm−2leads to complete removal of residual argon without segregation of carbon or other contaminants at the surface. However, irradiation at an elevated temperature ∼200 °C is required to obtain a well‐ordered surface. At elevated temperatures, laser annealing provides a surface with cleanness and surface order comparable to that obtained by conventional thermal annealing.

ISSN:0734-2101    

DOI:10.1116/1.572227

出版商:American Vacuum Society    

年代:1983

数据来源: AIP

摘要:

Optical information storage utilizing the explosive crystallization of amorphous In1−xGaxSb films is reported. Information encoding is accomplished using a low power, focused laser beam to crystallize local areas of the film by normal nucleation and grain growth. The remainder of the film is ‘‘developed’’ by spontaneously propagating an explosive crystallization (EC) front. The formation can be retrieved by rastering a low intensity laser beam across the storage media and detecting the difference in optical reflectivity between the roughened EC matrix and the smooth highly reflecting laser annealed regions. A 15:1 signal‐to‐noise ratio has been obtained in initial experiments with 5 μm diameter recorded spots. The spot temperature and laser power densities required for writing with this approach are expected to be lower than in comparable techniques where melting or vaporization is required.

ISSN:0734-2101    

DOI:10.1116/1.572228

出版商:American Vacuum Society    

年代:1983

数据来源: AIP