AVS 50th International Symposium
    Thin Films Monday Sessions
       Session TF-MoM

Paper TF-MoM10
Low Temperature Deposition of SiN using Sequential Exposures of Si@sub 2@Cl@sub 6@ and NH@sub 3@

Monday, November 3, 2003, 11:20 am, Room 329

Session: Atomic Layer Deposition
Presenter: J.W. Lim, Samsung Electronics, Korea
Authors: J.Y. Ahn, Samsung Electronics, Korea
J.G. Kim, Samsung Electronics, Korea
J.W. Lim, Samsung Electronics, Korea
H.S. Kim, Samsung Electronics, Korea
U. Chung, Samsung Electronics, Korea
J.T. Moon, Samsung Electronics, Korea
Correspondent: Click to Email
Low temperature deposition of SiN is required in many applications for fabrication of high performance MOSFET devices. SiN films were deposited by atomic layer deposition (ALD) and cyclic chemical vapor deposition (CVD) using sequential exposures of Si@sub 2@Cl@sub 6@ and NH@sub 3@ at temperatures ranging from 400 to 600°C. The films were deposited in a mini-batch reactor employing cross-wafer gas flow scheme for rapid delivery of precursors and rapid evacuation of reactants. The saturated growth rate of ALD-SiN was 2.2Å/cycle. The films were characterized by AES, AFM, FTIR, RBS, SIMS, SEM, spectroscopic ellipsometry and TEM. The wet etch and reactive ion etch (RIE) characteristics were also investigated. ALD-SiN films are smooth, highly conformal and stoichiometric. In addition, they contain less hydrogen than the conventional LPCVD-SiN films deposited at equivalent temperatures, and exhibit high etch selectivity to SiO@sub 2@. The RIE selectivity to SiO@sub 2@ was determined to be nearly constant within the temperature range of 400-600°C. The properties of the films deposited by cyclic CVD method, in which self-limited surface saturation is not obtained, were comparable to ALD-SiN, and the Si:N ratio of cyclic CVD-SiN is controllable in the range of 0.7 - 1.0 by varying the Si source exposure and dilution. The electrical properties of the ALD and cyclic CVD films were evaluated by performing I-V and C-V measurements with MIS (Metal Insulator Silicon) capacitor structures. The physical and electrical properties of cyclic CVD films deposited at 590°C were as good as the conventional LPCVD films deposited at 700°C using DCS/NH@sub 3@ chemistry, and therefore the thermal budget for device fabrication can be reduced using cyclic CVD-SiN. The suitability of ALD-SiN films deposited at 450°C was reviewed for fabrication of high performance CMOS devices employing NiSi module process.