Amorphous W-Zr films as diffusion barriers between Al and Si

Technical Report · Wed Jan 01 04:00:00 EST 1986

OSTI ID:5731932

So, F T; Zhao, X A; Kolawa, E; Tandon, J L; Zhu, M F

Cosputtered W70Zr30 and W40Zr60 films are investigated as diffusion barriers between Aq and Si. W-Zr alloys of both compositions were determined by x-ray diffraction to crystallize at 900/sup 0/C on A1/sub 2/O/sub 3/ substrates. On <111>Si the W-Zr alloy reacts with the substrate above 700/sup 0/C, forming a uniform, polycrystalline layer of W and Zr silicides. Despite the high crystallization temperatures, an A1 overlayer interacts with W-Zr and the Si substrate at approx. 500/sup 0/C. MeV He-backscattering spectrometry, SEM, and EDAX indicate that this reaction is laterally nonuniform with the formation of deep pits penetrating into the Si substrate. The authors believe this to be a consequence of fractures in the W-Zr layer induced by reaction with A1. Electrical measurements on shallow junction diodes with /W-Zr/Al contacts show that the device junctions were thermally stable after a 30 min annealing at 450/sup 0/C but were all shorted after heat treatments at 500/sup 0/C or above.

• Research Organization: California Inst. of Tech., Pasadena (USA)
• OSTI ID: 5731932
• Report Number(s): AD-A-184820/9/XAB
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360104 -- Metals &amp; Alloys-- Physical Properties
42 ENGINEERING
420800* -- Engineering-- Electronic Circuits &amp; Devices-- (-1989)
ALLOYS
DIFFUSION BARRIERS
ELEMENTS
FILMS
JUNCTION DIODES
PHYSICAL PROPERTIES
SEMICONDUCTOR DEVICES
SEMICONDUCTOR DIODES
SEMIMETALS
SILICON
THERMODYNAMIC PROPERTIES
THIN FILMS
TUNGSTEN ALLOYS
ZIRCONIUM ALLOYS