AVS 51st International Symposium
    Electronic Materials and Processing Monday Sessions
       Session DI-MoA

Paper DI-MoA10
A New Approach to the Synthesis of Zr Oxynitride Alloys: Chemical and Electrical Characterizations

Monday, November 15, 2004, 5:00 pm, Room 304B

Session: High-k Dielectrics: Electronic Properties
Presenter: B. Ju, NC State University
Authors: B. Ju, NC State University
G. Lucovsky, NC State University
Correspondent: Click to Email
In order to suppress chemical phase separation in Zr silicate alloys, (ZrO@sub 2@)@sub x@(SiO@sub 2@)@sub 1-x@, at temperatures up 900°C, N-atoms have been incorporated into these alloy films by a remote plasma assisted process. Our studies indicated that N-atoms were not incorporated uniformly by this plasma process. This paper provides an alternative synthesis route that produces uniform N-atom incorporation, and also prevents formation of O-N bonds that are observed in the plasma modified Zr silicate films. In this study, Zr-Si oxynitride [(ZrO@sub 2@)@sub x@(Si@sub 3@N@sub 4@)@sub y@(SiO@sub 2@)@sub z@], x+y+z = 1, pseudo-ternary alloy films have deposited on Si (100) wafers by low temperature (300°C) remote plasma enhanced chemical vapor deposition (RPECVD). Film compositions were determined by Rutherford back scattering (RBS) and these were used to calibrate on-line Auger electron spectroscopy (AES). In general, the ZrO@sub 2@ concentration could be held relatively constant for SiO@sub 2@ rich alloys, y < z, but decreased in the Si@sub 3@N@sub 4@ rich alloy regime in which y > z. The local bonding of Zr-, Si-, O- and N-atoms in as-deposited, and annealed Zr-Si oxynitride alloys were investigated by x-ray photoemission spectroscopy (XPS) as a function of alloy composition. Previous studies have indicated that changes in the O-atom 1s core level feature provided a way to detect chemical phase separation. In alloys with up to 20 % ZrO@sub 2@ fraction, no chemical phase separation or compositional changes were detected after rapid thermal annealing (RTA) up to 1100°C in Ar for 1 minute. Capacitance-voltage (C-V) and leakage-voltage (J-V) studies were performed on metal-oxide-semiconductor (MOS) capacitors fabricated on both n-type and p-type Si substrates, and these results will be presented in the paper.