Plasma-activated ion-beam reactive sputtering of NbN thin films

Technical Report · Fri Nov 25 04:00:00 EST 1988

OSTI ID:5376386

Lichtenwalner, D J; Anderson, A C; Rudman, D A

In order to better study and control the processes occurring in a reactive sputtering situation, a unique deposition method was used in which the Ar-ion-beam sputtering of an elemental Nb target is combined with an auxillary Ar/N{sub 2} plasma at the substrate. The ion source allows independent control of the sputtering parameters (ion flux, energy). The magnetically enhanced triode plasma provides a source of ionized and excited nitrogen at the film surface, and allows independent control of the substrate plasma parameters. A conductance-limiting enclosure surrounds the substrate, resulting in a pressure differential of nearly an order of magnitude between the substrate and target regions. This enables separation of the substrate and target-reaction regimes at low nitrogen flows. NbN was investigated because of its technological importance and the fact that it is representative of transition metal nitrides. With the substrate plasma off and N{sub 2} provided at the substrate, the cubic superconducting NbN (delta phase) is produced even at low N{sub 2} flows, when the target is in the unreacted, metallic state. Upon increasing the N{sub 2} flow, the nitrogen content of the films abruptly increases as the target reaction proceeds. The addition of the substrate plasma results in the nonsuperconducting hexagonal delta phase, which to the authors knowledge has not previously been produced as a single-phase thin film. The electrical properties of the delta phase are reported.

• Research Organization: Massachusetts Inst. of Tech., Lexington, MA (USA). Lincoln Lab.
• OSTI ID: 5376386
• Report Number(s): AD-A-210781/1/XAB; MS--8036
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360201* -- Ceramics
Cermets
& Refractories-- Preparation & Fabrication
BEAMS
CONTROL
DEPOSITION
ELECTRICAL PROPERTIES
ELEMENTS
FILMS
ION BEAMS
ION DENSITY
NIOBIUM COMPOUNDS
NIOBIUM NITRIDES
NITRIDES
NITROGEN
NITROGEN COMPOUNDS
NONMETALS
PHYSICAL PROPERTIES
PLASMA
PNICTIDES
REFRACTORY METAL COMPOUNDS
SPUTTERING
SUBSTRATES
SURFACES
TARGETS
THIN FILMS
TRANSITION ELEMENT COMPOUNDS