Epitaxial Growth of Al on Si by Gas-Temperature-Controlled Chemical Vapor Deposition

Abstract

Epitaxial Al(111) film was deposited on Si(111) by low-pressure chemical vapor deposition with the use of tri-isobutyl aluminum (TIBA) at the substrate temperature of 400°C with the deposition rete of 0.9 µm/min. It was necessary for epitaxy to preheat the TIBA gas just before the deposition on the substrate (gas-temperature controlling). The film surface was very smooth; reflectance was higher than 90%. Streaks were observed in RHEED patterns. The rocking curve measured by X-ray diffraction was very narrow. Analysis by SIMS showed the film contained about 0.1% of Si and 20 ppm of O, C, and H. No hillock appeared on the film after 430°C annealing for 40 min.

Aluminum chemical vapor deposition with new gas phase pretreatment using tetrakisdimethylamino-titanium for ultralarge-scale integrated-circuit metallization

“…Hence, the minimal radii of via holes able to be filled by conformal deposition are restricted by the thinnest of the continuous Al films. This is the highest reflectance value among all reported CVD Al films, except epitaxial growth films, 16 to the authors' knowledge. As a result, the holes will not be filled with continuous film, and poor electrical conductivity between the top and bottom of the holes will be obtained.…”

Importance of steps in heteroepitaxy: The case of aluminum on silicon

“…Al͑111͒/Si͑111͒ epitaxy was also reported with chemical vapor deposition at a substrate temperature of 400°C. 7 Heteroepitaxy of Al͑111͒ on Si͑111͒ requires accommodation of a 25% mismatch in their lattice constants. Based on high resolution cross-section transmission electron microscopy ͑TEM͒ of the Al/Si interface, it was concluded that Al͑111͒/ Si͑111͒ epitaxy with Al͓110͔/Si͓110͔ is accomplished by matching four Al planes to three Si planes.…”

Chemical vapor deposition of Al, Fe and of the Al13Fe4 approximant intermettalic phase

“…TIBA has been extensively studied as a precursor for deposition of Al films in the temperature range 200 o C -400 o C (Bent et al, 1989;Green et al, 1984;Kobayashi et al, 1988;Sekiguchi et al, 1988). The rate-determining step in the deposition of Al involves cleavage of the Al-C bond by a β-hydrogen elimination, but a competitive β-methyl elimination becomes significant at temperatures around 300 o C yielding C-contaminated films (Bent et al, 1989).…”