摘要:

Ion implantation has been successful in producing significant improvements in the wear resistance and fatigue endurance of metals such as steel, titanium, copper and electrodeposited chromium. Models to explain this behaviour in terms of the pinning of mobile dislocations are presented. Friction coefficients are also modified by ion implantation, and in the composite material cobalt-cemented tungsten carbide this effect is very strong, and is accompanied by a reduction in wear. Examples of the range of tools which have been improved by nitrogen ion implantation are given, and the review concludes with a description of the equipment developed for the industrial application of this process.

ISSN:0033-7579    

DOI:10.1080/00337578208222820

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

The results obtained in the research work on the electrochemical and corrosion behaviour of metals after surface modifications caused by directed energy sources, that is ion implantation and pulsed laser irradiations, are presented. The following investigations were made: (a) The corrosion behaviour of nitrogen and boron implanted iron at various surface concentrations, in sulphuric acid, chloride ions containing solutions and borate buffer solutions, (b) The electrochemical and corrosion behaviour of aluminium after pulsed laser irradiation.

ISSN:0033-7579    

DOI:10.1080/00337578208222821

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

It has been known for some years that ion bombardment of a material will bring about a redistribution of its constituents. This can take place by a direct recoil process or as a result of collisional relocation within the collision cascade, known as cascade mixing. Alternatively, there are several mechanisms of radiation enhanced diffusion which may occur if the temperature is sufficiently high. The time scales for these processes are very different. Recent developments have led to the exploration and use of these effects in order to introduce atoms from a coating layer into the substrate below by ion bombardment as an alternative to their direct implantation. This review attempts to clarify the physical processes that occur, and to describe some recent applications to contacts on silicon devices, wear resistant surfaces in titanium alloys, and to achieve corrosion resistance in iron and nickel.

ISSN:0033-7579    

DOI:10.1080/00337578208222822

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

The potential advantages of ion implantation have been exploited in virtually every kind of semiconductor device. Several commercially important devices owe their existence to this technique.

ISSN:0033-7579    

DOI:10.1080/00337578208222823

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

Dopant distribution, electrical activity and damage annealing of high-dose (∼5 × 1015cm2) Ga-implanted silicon samples annealed by conventional thermal annealing have been studied by alpha particle back-scattering, differential Hall effect and ellipsometry measurements. Back-scattering spectra show that there is no long tail of Ga atoms in the as-implanted samples. Upon annealing these samples the damaged amorphous layer recrystallizes at about 570°C by solid phase epitaxy. During the epitaxial regrowth the dopant atom distribution seems to be modified. Further, very high levels of electrical activaton of Ga-atoms (∼3 × 1020cm−3), much higher than the maximum solubility limit of Ga in Si (4.5 × 1019cm−3), is achieved by thermal annealing of the sample at ∼570°C. This is comparable to the doping achieved by laser annealing of the Ga implanted Si. All the above three measurements show that there is residual damage in the high dose (≳1015cm−2) implanted samples after the recrystallization at about 570°C. This may be related to strain in the lattice at the high concentrations of metastable substitutional Ga atoms. Annealing at higher temperature reduces the electrical activity of Ga atoms, possibly by driving out the metastably high substitutional concentrations of Ga-atoms into electrically inactive clusters or precipitates.

ISSN:0033-7579    

DOI:10.1080/00337578208222824

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

A method is proposed for the calculation of the range profile of ions implanted into a double layer substrate. Results of calculation for the case of boron implantation into silicon through silicon dioxide are presented. In the present method one first considers the situation obtaining if the silicon beneath the interface were replaced by oxide. The profile is then known from standard data. A computer program then optimizes summation of Gaussians to obtain the energy distribution of equivalent ions normally incident at the interface. This distribution is then used to calculate the range profile in the real case of silicon beneath the interface again using standard data. The assumption in this is that the energy distribution of equivalent ions normally incident at the interface is independent of the underlying material.

ISSN:0033-7579    

DOI:10.1080/00337578208222825

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

Ion implanted silicon planar varactor diodes of large capacitance variation ratio have been developed for UHF/VHF TV tuner circuits. The ratio of the capacitance variation achieved at 3 V to 25 V is between 6 and 7 with devices exhibiting low leakage and a required breakdown voltage of 30 V. Ion implantation has been used to introduce phosphorus into n-type silicon in the predeposition cycle. The device fabrication is completed using conventional diffusion techniques which also include thermal annealing. The fabrication process involves a minimum number of processing steps to produce low-cost devices. These diodes were used in a VHF TV tuner to obtain gain between 18 and 32 db in different bands, indicating high values of the quality factor of the varactors.

ISSN:0033-7579    

DOI:10.1080/00337578208222826

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

In the system of boron and carbon, the formation of boron carbide was investigated after ion implantation of 25 keV B ions into carbon or of 25 keV C ions into boron and subsequent annealing. TEM and electron diffraction studies showed that the crystallization of boron carbide begins only at temperatures above 1050°C. By implantation of 20 keV C ions into iron (ion dose 1017C ions/cm2) only the metastable ε-Fe2O will be generated, which at above 220°C transforms into the stable cementite Fe3C. After implantation of 20 keV B ions into iron, no formation of iron boride could be found. These experimental facts can be understood qualitatively with the help of the thermal-spike model. The energy density or the temperature in the thermal spikes is not sufficient for the generation of cementite iron boride or boron carbide.

ISSN:0033-7579    

DOI:10.1080/00337578208222827

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

Experimental results on changes in conductivity of N2+ and Ar+bombarded thin copper, aluminium and bismuth films are given along with the preliminary observations on photoconductivity of N2+ bombarded Bi2O3thin films. The performance of a low cost, medium resolution 200 keV ion implantation system, used in the above experiments is also discussed.

ISSN:0033-7579    

DOI:10.1080/00337578208222828

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

A simple procedure has been developed for high current ion implantation. In particular, no mass separation is used in the beam. The procedure is described in some detail, as well as the various characteristics of the implanted layers: ion distribution, damage (macroscopic and microscopic), effects of conventional and pulsed annealing. This technique has been employed for preparing solar cells on silicon. The properties of these devices will be reviewed and compared to conventionally prepared cells.

ISSN:0033-7579    

DOI:10.1080/00337578208222829

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor