Ultrathin SiOxNy by rapid thermal heating of silicon in N2 at T=760–1050 °C

In this letter, we report on the reaction between Si and N2 in the temperature range of 760–1050 °C, in a rapid thermal processing chamber. Gas phase impurities such as H2O, O2, and H2, which can outgas from the cold walls of the chamber, mediate the Si/N2 reaction, resulting in the formation of SiOxNy. The oxynitridation can be explained by equilibrium chemical thermodynamics, in contrast to the case of oxynitridation using N2O or NO, where the nitrogen is incorporated under nonequilibrium conditions. Using nuclear reaction analysis, we have measured nitrogen contents as high as 2.5×1015 N/cm2 (the equivalent of more than 3 monolayers) in these new dielectrics. They can be reoxidized to form ultrathin (2 to 3 nm) dielectrics.

[1]  W. M. Chen,et al.  Correlation of dielectric breakdown with hole transport for ultrathin thermal oxides and N2O oxynitrides , 1995 .

[2]  S. I. Raider,et al.  Nitrogen reaction at a silicon–silicon dioxide interface , 1975 .

[3]  A. Moulson,et al.  Nitridation of high-purity silicon , 1975 .

[4]  K. Rose,et al.  Conditions for Thermal Nitridation of Si in N 2 ‐ O 2 Mixtures , 1988 .

[5]  C. Araujo,et al.  Selective Oxidation Using Ultrathin Nitrogen‐Rich Silicon Surface Layers Grown by Rapid Thermal Processing , 1989 .

[6]  Toshimasa Matsuoka,et al.  Hot-carrier-induced degradation of N/sub 2/O-oxynitrided gate oxide NMOSFETs , 1996 .

[7]  Robert A. Buhrman,et al.  N depth profiles in thin SiO2 grown or processed in N2O: The role of atomic oxygen , 1995 .

[8]  Leonard C. Feldman,et al.  EFFECT OF INCORPORATED NITROGEN ON THE KINETICS OF THIN RAPID THERMAL N2O OXIDES , 1995 .

[9]  Y. Hayafuji,et al.  Nitridation of Silicon and Oxidized‐Silicon , 1982 .

[10]  H. Jennings.  On reactions between silicon and nitrogen , 1983 .

[11]  Hisashi Fukuda,et al.  Highly Reliable Thin Nitrided SiO2 Films Formed by Rapid Thermal Processing in an N2O Ambient , 1990 .

[12]  Martin L. Green,et al.  The composition of ultrathin silicon oxynitrides thermally grown in nitric oxide , 1997 .

[13]  Leonard C. Feldman,et al.  Rapid thermal oxidation of silicon in N2O between 800 and 1200 °C: Incorporated nitrogen and interfacial roughness , 1994 .

[14]  R. E. Tressler,et al.  Thermodynamics of the Si‐N‐O System and Kinetic Modeling of Oxidation of Si3 N 4 , 1989 .

[15]  Jack C. Lee,et al.  Electrical and reliability characteristics of ultrathin oxynitride gate dielectric prepared by rapid thermal processing in N/sub 2/O , 1990, International Technical Digest on Electron Devices.

[16]  E. P. Gusev,et al.  Effect of near-interfacial nitrogen on the oxidation behavior of ultrathin silicon oxynitrides , 1997 .

[17]  H. B. Harrison,et al.  High quality ultrathin dielectric films grown on silicon in a nitric oxide ambient , 1994 .

[18]  Z. Lu,et al.  Rapid thermal N2O oxynitride on Si(100) , 1996 .

[19]  Leonard C. Feldman,et al.  Nitrogen content of oxynitride films on Si(100) , 1994 .

[20]  Martin L. Green,et al.  Thickness dependence of boron penetration through O/sub 2/- and N/sub 2/O-grown gate oxides and its impact on threshold voltage variation , 1996 .

[21]  Hiroshi Iwasaki,et al.  Electrical and physical properties of ultrathin reoxidized nitrided oxides prepared by rapid thermal processing , 1989 .

[22]  Sergio A. Ajuria,et al.  Furnace grown gate oxynitride using nitric oxide (NO) , 1994 .

[23]  E. J. Lloyd,et al.  High performance 0.2 /spl mu/m CMOS with 25 /spl Aring/ gate oxide grown on nitrogen implanted Si substrates , 1996, International Electron Devices Meeting. Technical Digest.

[24]  P. Debenest,et al.  Boron diffusion through thin gate oxides: Influence of nitridation and effect on the Si/SiO2 interface electrical characteristics , 1993 .

[25]  S. Hijiya,et al.  Very Thin Silicon Nitride Films Grown by Direct Thermal Reaction with Nitrogen , 1978 .

[26]  Mats Hillert,et al.  Thermodynamic Calculation of the SI - Al-O -N System / Thermodynamische Berechnung des Systems Si-Al-O-N , 1992 .

[27]  Nelson S. Saks,et al.  Nitrogen depletion during oxidation in N2O , 1995 .

[28]  Leonard C. Feldman,et al.  High resolution ion scattering study of silicon oxynitridation , 1996 .

[29]  P. Rushbrook,et al.  The performance and reliability of 0.4 micron MOSFET's with gate oxynitrides grown by rapid thermal processing using mixtures of N/sub 2/O and O/sub 2/ , 1994 .