Growth of Ru/RuO2 layers with atomic vapor deposition on plain wafers and into trench structures

• Published in: Microelectronic engineering Vol. 83; no. 11-12; pp. 2277 - 2281
• Main Authors: MANKE, C, BOISSIERE, O, WEBER, U, BARBAR, G, BAUMANN, P. K, LINDNER, J, TAPAJNA, M, FRÖHLICH, K
• Format: Conference Proceeding Journal Article
• Language: English
• Published: Amsterdam Elsevier Science 01.11.2006
• Subjects: Applied sciences; Electronics; Exact sciences and technology; Materials; Atomic layer method; Trench technology; Ruthenium; Roughness; Transistor gate; Multiple layer; Step method; Atomic vapor deposition; Ruthenium oxide; Aspect ratio; Thin film; AVD; Vapor deposition; Sheet resistivity; Metal gate stack; Root mean square value; Smooth surface; Wafer
• ISSN: 0167-9317; 1873-5568
• DOI: 10.1016/j.mee.2006.10.018

Using beta-diketonate Ru precursors diluted in n-octane Ru and RuO2 layers were grown on plane 200 nm SiO2/Si wafers by atomic vapor deposition (AVD). AVD was carried out in an AIXTRON Tricent system using liquid delivery of the ruthenium precursor. The deposited multi-crystalline smooth (RMS surface roughness < 1 nm) Ru layers are preferable orientated along the (002) plane and exhibit a near bulk sheet resistivity of around 10 muOmega cm for 20 nm films with a uniformity better than 1.5%. By adding oxygen during the AVD process homogenous multi-crystalline RuO2 films are processed with a sheet resistivity of about 80 muOmega cm (for 30 nm layer thickness) and uniformity better than 2%. Growth of Ru into trench structures is achieved by working with a pure Ru precursor in its kinetic growth regime. Highly conformal Ru thin films were deposited at 300 deg C-320 deg C on trench structures. Depending on the deposition parameters like reactor pressure, injection frequency and opening time good Ru step coverage in trenches is achieved. More than 90% step coverage is obtained for structures with aspect ratios of 1:10.