A new EPR spectrum, arising from defects in diamond created by boron, carbon, and nitrogen ion-implantation, is observed. The spectrum, lattice damage production, and annealing of damage are discussed and are ascribed to amorphous carbon.Ein neues EPR-Spektrum in Diamant wird beobachtet, das von Storstellen herruhrt, die durch Ionenimplantation von Bor, Kohlenstoff und Stickstoff erzeugt wurden. Das Spektrum, die Erzeugung und das Ausheilen der GitterschLden werden diskutiert und dem amorphen Kohlenstoff zugeschrieben.

A process for fabricating experimental Josephson integrated circuits is described that is based primarily on the use of vacuum-deposited Pb-alloy and SiO films patterned by photoresist stencil lift-off. The process has evolved from one previously reported, with changes having occurred injunction electrodes, tunnel barrier formation, layer patterning, device geometry, and minimum linewidths. Films of Pb-In{l2 wt%)-Au(4 wt%) alloy (200-800 nm thick) are used for forming junction base electrodes, interferometer controls, and interconnection lines. Tunnel barriers are formed on the base electrode films by thermal oxidation and subsequent sputter-etching in an rf-oxygen plasma. Junction counter electrodes are formed from 400-nm-thick Pb-Bi(29 wt%) alloy films. Ground planes are formed from 300-nm-thick Nb films patterned by subtractive etching and insulated in part by a Nbfi. layer formed by liquid anodization. Films of the intermetallic compound Auln,^ (30-43 nm thick) are used for forming terminating, load, and damping resistors. The SiO films are used for interlayer insulation, for defining junction areas in interferometers, and as protective coatings. Layer patterning is achieved mainly by means of photoresist lift-off stencils. By utilizing this process, experimental logic and memory circuits containing =^100 interferometers with lines as small as 2.5 p-m in width have been successfully fabricated.

C+ and N+ implantation into type IIa diamond are performed at various temperatures (25 to 1000°C) and ion‐induced damage is studied by EPR measurements at 1.2 to 300 K. Hot implantation at 1000°C results in a reduced spin density of “amorphous” carbon by an order of magnitude less than that due to cold‐implantation and a subsequent annealing at 1000°C. Moreover, hot implantation above 600°C produces two new spin‐1 centers, A‐5 and A‐6, which are tentatively identified as a small multivacancy cluster.

Amorphous carbon layer EPR measurements have been fitted to a model which predicts the critical fluences at which the layer forms for any temperature and ion species; it predicts the layer will not form during nitrogen ion implantation in diamond above 1031°K. A new anisotropic EPR spectrum labeled D‐A4 is observed after hot‐implantation (650°C) with nitrogen ions. It is thought to be a spin‐one‐center arising from a small D‐tensor interaction with 〈111〉 symmetry. Hot implantation suppresses the formation of the amorphous layer and enhances creation of crystalline lattice defects.

A man-made boron doped diamond has been irradiated at 77 K with 1.5 MeV electrons. After irradiation an isotropic signal is observed which is composed of a central resonance at g = 2.00 and of a two line spectrum (A 7) split symmetrically 60 G from the central line. After sufficient annealing an additional two line spectrum (A 8) split symmetrically 33 G from the central line appears. The variation with dose and with isochronal annealing (up to 330 K) of these spectra is measured. Their annealing behaviour is correlated with previously published conductivity measurements, demonstrating that the A 7 and A 8 spectra are associated with the thermal deexcitation of traps present before irradiation and that an annealing stage of the central line at 250-300 K is associated with the recovery of irradiation-induced defects. The defects associated with these spectra have not been identified