摘要:

Selection of large‐scale functional film‐coating systems involves many parameters that are not always obvious. This paper will attempt to cover many of these in some detail. Consideration will be given to specification of the system, process variables, process monitors, computer interfacing, and cost‐performance analysis. An example of such an analytical method will be given that covers in detail both the generation of a system specification and its quantitative analysis.

ISSN:0022-5355    

DOI:10.1116/1.569164

出版商:American Vacuum Society    

年代:1977

数据来源: AIP

摘要:

A comparison of triode and diode noble‐gas sputter‐ion pumps was performed to determine the advantages and disadvantages of each technique. Pumping speed measurements using nitrogen and argon were obtained over the range of 5×10−9to 1×10−4Torr (6.7×10−7to 1.3×10−2Pa) and long term characteristics were obtained by pumping Ar continuously at 1×10−5Torr (1.3×10−3Pa) until pump failure occurred. The triode has advantage at high pressure while the diode exhibits better pumping speed at low pressure. Accelerated life testing showed the diode pump to have a more stable pumping characteristic with time.

ISSN:0022-5355    

DOI:10.1116/1.569165

出版商:American Vacuum Society    

年代:1977

数据来源: AIP

摘要:

Strontium and calcium getters have possible use replacing barium as gas sorbers in color picture tubes and other electron tubes. Stable getters were made of a calcium–aluminum or strontium–aluminum alloy, which was powdered, mixed with nickel powder, and pressed into a ring‐shaped channel of stainless steel. After exhaust pumping and tip‐off of the picture tube, the getter was heated to form a gas‐sorbing film of strontium or calcium, which was deposited by evaporation onto the internal surfaces of the picture tube. Strontium and calcium getters were evaluated and compared to barium getters in color picture tubes by the oxygen sorbtion test, which determined the maximum oxygen quantity that can be absorbed by the film without damage to the tube’s oxide cathode. When flashed in 25‐in. color tubes, barium and strontium showed the same oxygen capacity, both initially and after 11 and 25 weeks of life test. When flashed in tubes of smaller size and surface area, strontium showed lower oxygen capacity than barium, a result indicating slower bulk diffusion of oxygen through thick films of strontium oxide than through barium oxide. Calcium showed satisfactory gettering speed allowing normal tube operation out to 25 weeks of life test; however its gettering capacity was lower, being about 1/4 that of barium and indicating even slower diffusion of oxygen in calcium oxide than in strontium oxide.

ISSN:0022-5355    

DOI:10.1116/1.569166

出版商:American Vacuum Society    

年代:1977

数据来源: AIP

摘要:

A pumping system using commerical components is described which has been found to be convenient for growth of doped silicon films by molecular‐beam epitaxy. The system consists of an aspirator operated with dry nitrogen gas, molecular‐sieve sorption pumps, and a charcoal absorber surrounded by liquid‐nitrogen‐cooled walls and cooled to temperatures as low as 10 K by a refrigerator using helium as the refrigerant medium. Starting with a stainless‐steel chamber of 80‐l volume at 760 Torr (1×105Pa), a residual pressure of 2×10−10Torr (2.7×10−3Pa) is attained after a 12‐h bakeout at 150°C. The cryopump is capable of accepting the argon flow required for sputter cleaning of the substrates. During the operation of anegun for the evaporation of molten silicon, increases in pressure resulting almost entirely from hydrogen evolution are held below 3×10−8Torr (4×10−6Pa). Advantages of this system are freedom from contamination by pump fluids, minimum requirements for services and maintenance, and relatively high speed in relation to physical size.

ISSN:0022-5355    

DOI:10.1116/1.569167

出版商:American Vacuum Society    

年代:1977

数据来源: AIP

摘要:

We have designed, built, and tested a cryogenic chamber capable of pressures far below 10−14Torr (∠10−12Pa) for surface studies. In a conventional vacuum system the surface desorbing and diffusing/desorbing vapors enter the chamber and are pumped to a dynamic equilibrium pressure by an ion pump or a cryopumping surface. In contrast, in the present system these vapors are prevented from first entering the cubic‐foot chamber by cooling to 4.2 Kallwalls andallinstruments sealed within it. This results in a nearly perfect vacuum (<1 atom/cm3), which has been used to preserve sample surfaces, between measurements (i.e., 60 days). At higher chamber temperatures we have used aninsituquadrapole mass analyzer to measure the equilibrium partial pressures from 300 down to ∠30 K, where the last two gases, hydrogen and helium, drop below the instrument’s detectability limit.

ISSN:0022-5355    

DOI:10.1116/1.569168

出版商:American Vacuum Society    

年代:1977

数据来源: AIP

ISSN:0022-5355    

DOI:10.1116/1.569169

出版商:American Vacuum Society    

年代:1977

数据来源: AIP

摘要:

Evaporation of Al–Cu alloy is accomplished by codeposition from a crucible heated by rf induction. This paper presents a discussion of the mechanisms affecting the amount of copper deposited on the substrates. Knowledge of this is used to structure a loading scheme to insure long crucible life in terms of run‐to‐run variation in copper content. In addition, some data is presented to demonstrate the successful application of this method. Thsi paper also discusses possible comparisons of this work to the theoretical calculations of Zinsmeister, who developed the application of Raoult’s law to evaporation of alloys.

ISSN:0022-5355    

DOI:10.1116/1.569170

出版商:American Vacuum Society    

年代:1977

数据来源: AIP

摘要:

The effects of process parameters on the formation of the titanium films were studied and some properties of the coatings (such as hardness, morphology, porosity, corrosion resistance, and adhesion) were examined. The titanium coatings deposited on steel substrates were prepared by ion‐plating techniques using a diode system with electron‐beam heating of the source materials. Knoop hardness of ion‐plated titanium coatings formed for 3 min at negative bias of 3 kV, process pressure of 1.3×10−3Pa, and substrate temperature of 150°C, showed higher values as compared with the value of an annealed pure titanium sheet. The porosity of these coating was considerably affected by the coating thickness. The titanium coatings above 5 μm of the thickness indicated a satisfactory corrosion resistance in 3%‐NaCl aqueous solution. The ion‐plated titanium coatings showed better adhesion to steel substrates than coatings obtained by conventional vacuum vapor deposition.

ISSN:0022-5355    

DOI:10.1116/1.569171

出版商:American Vacuum Society    

年代:1977

数据来源: AIP

摘要:

Thin gold films were vapor deposited onto KCl single crystals under a variety of substrate temperatures, residual gas pressures, and deposition rates. The films were subsequently examined by high‐resolution transmission‐electron microscopy. The use of the defocus contrast technique revealed a large number of small (10–50 Å in size) voids in all of the films investigated. The void density and total void volume were found to be highly sensitive to the substrate temperature and only moderately sensitive to the residual gas pressure during the deposition. Typical values of the void density in films prepared at a residual gas pressure of 10−7Torr (∠10−5Pa) ranged from the order of 1010/cm2at a substrate temperature of 280° C to that of 1011/cm2at 55° C. Similar results were obtained for a residual gas pressure of 10−4Torr (∠10−2Pa).

ISSN:0022-5355    

DOI:10.1116/1.569172

出版商:American Vacuum Society    

年代:1977

数据来源: AIP

摘要:

X‐ray photoelectron spectroscopy (ESCA) has been employed to examine several elemental metal foils which were simultaneously allowed to develop natural passivation (oxidation) layers. The metals considered included representative transition metals and also several Group III and IV elements. Sputter etching was employed to establish approximate depth profiles. Highly reproducible results for the individual components made it possible to identify all of the major constituents. These results have yielded new information in the metallurgy and surface science of these systems. In order to properly study these systems, we have found it necessary to use an electron flood gun capable of removing the charge shifts from the passivation (insulator) layers. The study demonstrates the feasibility of ESCA as a tool for industrial metallurgical problems.

ISSN:0022-5355    

DOI:10.1116/1.569174

出版商:American Vacuum Society    

年代:1977

数据来源: AIP