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Dc and rf magnetron sputter deposition of NbN films with simultaneous control of the nitrogen consumption
Classified abstracts 6532-6540 21 6532. Reactive synthesis of well-oriented zinc-oxide films by means of the facing targets sputtering method Well-oriented ZnO films are reactively synthesized by means of the facing targets sputtering (FTS) method. In this paper, the change in the crystallographic characteristics o f ZnO films with respect to sputtering conditions are described in detail. Films obtained by means of the FTS method exhibit one of the best c-axis orientations reported to date. The following conditions are necessary for formation of well-oriented ZnO films with good surface smoothness: (1) High-energy particle bombardment on the film surface during deposition should be suppressed and (2) the sputtered particles landing on the substrate surface should have an appropriate energy level of several eV. Morito Matsuoka et al, J appl Phys, 63, 1988, 2098~103. 21 6533. De and rf magnetron sputter deposition of NbN films with simultaneous control of the nitrogen consumption To obtain high-quality N b N films with reproducible properties standard dc and rf magnetron sputter-deposition techniques were applied. As a sputtering gas a mixture of nitrogen and argon was used. The actual amount of nitrogen in the chamber is monitored by a differentially pumped mass spectrometer. The dependence of the nitrogen partial pressure on the amount of nitrogen injected into the chamber and the electrical power yields information about the target reaction with the nitrogen. In order to find the best preparation parameters, the interdependence between electrical sputtering power, nitrogen flow, nitrogen consumption, and the superconducting properties of the N b N films was investigated. H-J Hedhabny and H Rogalla, J appl Phys, 63, 1988, 2086-2090.
22. THIN FILM ADHESION 22 6534. High temperature microhardness of hard coatings produced by physical and chemical vapor deposition The microhardness of hard coatings of TiN and HfN prepared by chemical vapor deposition (CVD) and of TiN, HfN, ZrN and TiA1N prepared by physical vapor deposition (PVD) were measured between room temperature and 1000°C. The microhardness of the PVD coatings was significantly higher than that of the CVD counterparts at room temperature but all microhardness values tended to converge at 1000°C. Higher N : Ti ratios were found in PVD TiN relative CVD TiN. X-ray diffraction measurements indicated that the PVD coatings contained high residual compressive growth stresses associated with lattice distortion and very fine grain size, which were confirmed using transmission electron microscopy. Low residual stresses in high temperature CVD coatings are caused by thermal expansion mismatch between coating and substrate. Differences in grain morphology and crystal texture are attributed to varying conditions of energetic bombardment and deposition temperature in the several PVD methods employed. The faster decrease in microhardness with temperature in PVD coatings is caused by the high residual energy and finer grain size. Dennis T Quinto et al, Thin Solid Films, 153, 1987, 19-36. 22 6535. Structure, internal stresses, adhesion and wear resistance of sputtered alumina coatings Thin alumina coatings have been produced by means of reactive r.f. magnetron sputtering. The layers, deposited onto metallic substrates, show an amorphous crystallographic structure. Scanning electron microscopy analysis shows that the structure is variable within a wide range, from rough fibrous to smooth glass like, depending on the deposition parameter. Measurement of internal stresses was performed by using the bending beam method. The magnitude of the measured compressive stresses depends on the film thickness, deposition pressure and sputtering power. Some correlations between internal stress and adhesion of the coatings are evident. As well as scratch-test measurements the amount of layer detachment of bending specimens gave information about the adhesion behaviour of the coatings. Some of the alumina coatings have been tested with regard to their tribological behaviour by means of a model testing apparatus. The coatings showed excellent wear behaviour even under severe tribological conditions. Th Roth et al, Thin Solid Films, 153, 1987, 123 133.
22 6536. Adhesion and structure of TiN arc coatings TiN coatings were deposited with the arc technique at different substrate temperatures (200-450°C) and different bias voltages (0-400 V). The adhesion of the coatings on HSS substrates was then determined using the scratch test. The structures were recorded by scanning electron micrographs of the fracture surfaces. This showed that, in the case of arc coatings, the critical load increases more substantially with increasing temperature than with the increasing bias voltage, except from 0 to 100 V. Coatings deposited at a substrate temperature of 200°C exhibit a relatively high average critical load of 60 N and an unusually dense structure. Critical load values of more than 90 N can be obtained at higher substrate temperatures of around 450°C. As the result of a bias voltage of only 100 V, the adhesion increases by more than a factor of 2 compared with the unbiased condition, and simultaneously the droplet frequency decreases. At higher bias voltages, arc coatings become fine grained and exhibit a nearly equiaxed structure. Furthermore, partial epitaxial growth can be detected at the interface, When compared with triode-ion-plated TiN coatings from parallel production, arc coatings exhibit a better adhesion (higher critical loads). E Ertiirk and H - J Heuvel, Thin Solid Films, 153, 1987, 135-147. 22 6537. Yotmg's modulus of TiN, TiC, ZrN and HfN The Young's modulus of group IVB nitride and TiC films coated onto stainless steel substrates by reactive sputtering has been derived from their flexural resonance frequency. The values found for stoichiometric ZrN and HfN are 460 GPa and 380 GPa respectively. A wide range of TiN compositions was studied: the modulus increases steadily with nitrogen level to be about 640 GPa at the stoichiometric composition. A limited number of TiC samples has been measured; taking existing literature values into account a value for the stoichiometric phase of 460 GPa is derived. E T6r6k et al, Thin Solid Films, 153, 1987, 3743. 22 6538. Wear resistance of metastable Ni-B alloys produced by chemical vapor deposition A manufacturing application of the chemical vapor deposition of nickel from Ni(COh is the near-net-shape production of high-quality mold or die forms. In certain high wear applications, e.g. transfer molding of a glass-filled epoxy, erosive wear of the nickel die can compromise dimensional control of the product. We have investigated the atmospheric pressure deposition (at 15(~155°C) of Ni-B from Ni(CO)4+B2H6 gas mixtures in order to develop alloys with improved hardness and wear resistance. The as-deposited alloys are metastable solid solutions of boron in nickel and contain up to 37 at.% B. Evaluations of the alloys in the as-deposited and annealed states have included micro-indentation hardness and 1000-cycle pin-on-disc wear and friction studies using glassfilled epoxy pins. Two high boron alloys are shown to provide excellent resistance to wear when sliding against the glass-filled epoxy. Arthur W Mullendore and Larry E Pope, Thin Solid Films, 153, 1987, 267 279. 22 6539. Properties and performance of chemical vapour-deposited TiC-coated ball-hearing components TiC is an attractive coating material for bearing components because of its good wear resistance (Vickers' hardness 35,000 N mm 2) and its low coefficient of friction against steel. Because of their extreme surface hardness and fine single-phase microstructure, TiC-coated 440C steel balls can be lapped to surface qualities which are much better than the highest precision grade 3 specifications. When polished, TiC-coated 440C steel balls are compared with uncoated steel balls originating from two different producers; it is observed that the coated steel balls have a definitely superior surface quality. In bearings which are conventionally lubricated with oil and grease, TiC-coated balls provide lower vibration and noise levels and a longer useful lifetime o f the lubricant and therefore of the bearings themselves. Such coated balls can be used successfully in bearings to ensure trouble-free running under extreme environmental conditions, e.g. when no oil grease lubrication can be used. H J Boring and H E Hintermann, Thin Solid Films, 153, 1987, 253 266. 22 6540. A study of crack initiation and propagation in Ni Cr thermally sprayed coatings using acoustic emission techniques Many metallurgical coatings applied to thermal spraying tend to exfoliate 499
22. THIN FILM ADHESION 22 6534. High temperature microhardness of hard coatings produced by physical and chemical vapor deposition The microhardness of hard coatings of TiN and HfN prepared by chemical vapor deposition (CVD) and of TiN, HfN, ZrN and TiA1N prepared by physical vapor deposition (PVD) were measured between room temperature and 1000°C. The microhardness of the PVD coatings was significantly higher than that of the CVD counterparts at room temperature but all microhardness values tended to converge at 1000°C. Higher N : Ti ratios were found in PVD TiN relative CVD TiN. X-ray diffraction measurements indicated that the PVD coatings contained high residual compressive growth stresses associated with lattice distortion and very fine grain size, which were confirmed using transmission electron microscopy. Low residual stresses in high temperature CVD coatings are caused by thermal expansion mismatch between coating and substrate. Differences in grain morphology and crystal texture are attributed to varying conditions of energetic bombardment and deposition temperature in the several PVD methods employed. The faster decrease in microhardness with temperature in PVD coatings is caused by the high residual energy and finer grain size. Dennis T Quinto et al, Thin Solid Films, 153, 1987, 19-36. 22 6535. Structure, internal stresses, adhesion and wear resistance of sputtered alumina coatings Thin alumina coatings have been produced by means of reactive r.f. magnetron sputtering. The layers, deposited onto metallic substrates, show an amorphous crystallographic structure. Scanning electron microscopy analysis shows that the structure is variable within a wide range, from rough fibrous to smooth glass like, depending on the deposition parameter. Measurement of internal stresses was performed by using the bending beam method. The magnitude of the measured compressive stresses depends on the film thickness, deposition pressure and sputtering power. Some correlations between internal stress and adhesion of the coatings are evident. As well as scratch-test measurements the amount of layer detachment of bending specimens gave information about the adhesion behaviour of the coatings. Some of the alumina coatings have been tested with regard to their tribological behaviour by means of a model testing apparatus. The coatings showed excellent wear behaviour even under severe tribological conditions. Th Roth et al, Thin Solid Films, 153, 1987, 123 133.
22 6536. Adhesion and structure of TiN arc coatings TiN coatings were deposited with the arc technique at different substrate temperatures (200-450°C) and different bias voltages (0-400 V). The adhesion of the coatings on HSS substrates was then determined using the scratch test. The structures were recorded by scanning electron micrographs of the fracture surfaces. This showed that, in the case of arc coatings, the critical load increases more substantially with increasing temperature than with the increasing bias voltage, except from 0 to 100 V. Coatings deposited at a substrate temperature of 200°C exhibit a relatively high average critical load of 60 N and an unusually dense structure. Critical load values of more than 90 N can be obtained at higher substrate temperatures of around 450°C. As the result of a bias voltage of only 100 V, the adhesion increases by more than a factor of 2 compared with the unbiased condition, and simultaneously the droplet frequency decreases. At higher bias voltages, arc coatings become fine grained and exhibit a nearly equiaxed structure. Furthermore, partial epitaxial growth can be detected at the interface, When compared with triode-ion-plated TiN coatings from parallel production, arc coatings exhibit a better adhesion (higher critical loads). E Ertiirk and H - J Heuvel, Thin Solid Films, 153, 1987, 135-147. 22 6537. Yotmg's modulus of TiN, TiC, ZrN and HfN The Young's modulus of group IVB nitride and TiC films coated onto stainless steel substrates by reactive sputtering has been derived from their flexural resonance frequency. The values found for stoichiometric ZrN and HfN are 460 GPa and 380 GPa respectively. A wide range of TiN compositions was studied: the modulus increases steadily with nitrogen level to be about 640 GPa at the stoichiometric composition. A limited number of TiC samples has been measured; taking existing literature values into account a value for the stoichiometric phase of 460 GPa is derived. E T6r6k et al, Thin Solid Films, 153, 1987, 3743. 22 6538. Wear resistance of metastable Ni-B alloys produced by chemical vapor deposition A manufacturing application of the chemical vapor deposition of nickel from Ni(COh is the near-net-shape production of high-quality mold or die forms. In certain high wear applications, e.g. transfer molding of a glass-filled epoxy, erosive wear of the nickel die can compromise dimensional control of the product. We have investigated the atmospheric pressure deposition (at 15(~155°C) of Ni-B from Ni(CO)4+B2H6 gas mixtures in order to develop alloys with improved hardness and wear resistance. The as-deposited alloys are metastable solid solutions of boron in nickel and contain up to 37 at.% B. Evaluations of the alloys in the as-deposited and annealed states have included micro-indentation hardness and 1000-cycle pin-on-disc wear and friction studies using glassfilled epoxy pins. Two high boron alloys are shown to provide excellent resistance to wear when sliding against the glass-filled epoxy. Arthur W Mullendore and Larry E Pope, Thin Solid Films, 153, 1987, 267 279. 22 6539. Properties and performance of chemical vapour-deposited TiC-coated ball-hearing components TiC is an attractive coating material for bearing components because of its good wear resistance (Vickers' hardness 35,000 N mm 2) and its low coefficient of friction against steel. Because of their extreme surface hardness and fine single-phase microstructure, TiC-coated 440C steel balls can be lapped to surface qualities which are much better than the highest precision grade 3 specifications. When polished, TiC-coated 440C steel balls are compared with uncoated steel balls originating from two different producers; it is observed that the coated steel balls have a definitely superior surface quality. In bearings which are conventionally lubricated with oil and grease, TiC-coated balls provide lower vibration and noise levels and a longer useful lifetime o f the lubricant and therefore of the bearings themselves. Such coated balls can be used successfully in bearings to ensure trouble-free running under extreme environmental conditions, e.g. when no oil grease lubrication can be used. H J Boring and H E Hintermann, Thin Solid Films, 153, 1987, 253 266. 22 6540. A study of crack initiation and propagation in Ni Cr thermally sprayed coatings using acoustic emission techniques Many metallurgical coatings applied to thermal spraying tend to exfoliate 499