In situ x-ray diffraction observation of multiple texture turnovers in sputtered Cr films

• Published in: Journal of vacuum science & technology. A, Vacuum, surfaces, and films Vacuum, surfaces, and films, 2004-11, Vol.22 (6), p.2365-2372
• Main Authors: Zhao, Z. B., Rek, Z. U., Yalisove, S. M., Bilello, J. C.
• Format: Article
• Language: English
• Subjects: CHROMIUM; CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; CRYSTAL STRUCTURE; MAGNETRONS; REACTION KINETICS; SILICON OXIDES; SPUTTERING; TEXTURE; THIN FILMS; VAPOR DEPOSITED COATINGS; X-RAY DIFFRACTION
• ISSN: 0734-2101; 1520-8559
• DOI: 10.1116/1.1804984

A series of Cr films were deposited onto native oxides of (100) Si substrates via a confocal deposition geometry in a magnetron sputter chamber. The film growth chamber was incorporated with an in situ x-ray diffraction system, which allowed the collection of x-ray diffraction data on the growing film in a quasi real time fashion without interruption of film deposition. The in situ x-ray diffraction, coupled with other ex situ characterization techniques, was used to study structural evolutions of the Cr films deposited at various Ar pressures. It was observed that the evolution of the crystallographic structures of Cr films was very sensitive to both deposition conditions and film thickness. With the confocal deposition geometry, the Cr films developed various types of out-of-plane textures. In addition to the (110) and (100) types of textures commonly reported for vapor deposited Cr films, the (111) and (112) types of textures were also observed. The film deposited at low Ar pressure ( 2 mTorr ) developed strong (111) type texture. With the increase in either Ar pressure or film thickness, the Cr films tended to develop (112) and (100) types of texture. At high Ar pressures ( > 10 mTorr ) , several changes in texture type with increasing film thickness were observed. The sequence can be described as ( 110 ) → ( 112 ) → ( 100 ) . The strong tendency for these films to ultimately assume the (100) type of texture could be related to significant rises in substrate temperatures during the late stages of film growth with high Ar pressures. The observation of the multiple texture type changes suggests that the evolution of Cr films is controlled by complex growth kinetics. The competitive growth of grains with different orientations can be altered not only by controllable deposition parameters such as Ar pressure, but also by the variations of in situ film attributes (e.g., residual stress and substrate temperature) occurring concurrently with film growth.