The use of titanium-based contact barrier layers in silicon technology

Abstract The requirements on contact metallurgy for high performance very-large-scale integrated circuit technology have become more and more stringent because of the need for shallow junctions less than 0.25 μm in depth and contact sizes of the order of 1 μm 2 or smaller. A deposition of aluminum directly onto single-crystal silicon or onto a metal silicide can no longer satisfy the needs to achieve a stable and reliable contact. The use of a diffusion barrier layer in the contact structure, which prevents metallurgical reactions as well as diffusion between the silicon or silicide and the contact metal, is the most common approach to achieve stable and reliable contacts. The general requirements of such an effective contact barrier will be discussed. Early contact structures as well as diffusion barrier materials currently used in aluminum metallization, such as titanium, W/Ti and TiW, are reviewed and their performance is compared with that of TiN as a contact barrier layer.

[1]  G. Gurp,et al.  Aluminum‐silicide reactions. II. Schottky‐barrier height , 1979 .

[2]  I. V. Mitchell,et al.  Studies of the Ti-W/Au metallization on aluminum , 1978 .

[3]  C. J. Kircher,et al.  Contact metallurgy for shallow junction Si devices , 1976 .

[4]  H. Hosack.  Electrical and mechanical features of the platinum silicide‐aluminum reaction , 1973 .

[5]  Platinum silicide‐aluminum Schottky diode characteristics , 1972 .

[6]  M. Nicolet,et al.  Chromium thin film as a barrier to the interaction of Pd2Si with Al , 1977 .

[7]  L. Hartsough.  Resistivity of bias-sputtered TiW films , 1979 .

[8]  James A Cunningham,et al.  Corrosion Resistance of Several Integrated-Circuit Metallization Systems , 1970 .

[9]  H. Sankur,et al.  Diffusivity and Solubility of Si in the Al Metallization of Integrated Circuits , 1971 .

[10]  H. H. Berger,et al.  Contact Resistance and Contact Resistivity , 1972 .

[11]  G. Y. Robinson,et al.  Aluminum/nickel silicide contacts on silicon , 1978 .

[12]  C. Ting.  TiN formed by evaporation as a diffusion barrier between Al and Si , 1982 .

[13]  G. K. Herb,et al.  TiN as a diffusion barrier in the Ti-Pt-Au beam-lead metal system , 1978 .

[14]  M.-A. Nicolet,et al.  Investigation of titanium—nitride layers for solar-cell contacts , 1980, IEEE Transactions on Electron Devices.

[15]  Robert W. Bower,et al.  Characteristics of aluminum‐titanium electrical contacts on silicon , 1973 .

[16]  J. O. Mccaldin,et al.  Solid‐state growth of Si to produce planar surfaces , 1976 .

[17]  Y. Tamminga,et al.  Aluminum‐silicide reactions. I. Diffusion, compound formation, and microstructure , 1979 .

[18]  P. A. Totta,et al.  SLT device metallurgy and its monolithic extension , 1969 .

[19]  M. Wittmer.  High-temperature contact structures for silicon semiconductor devices , 1980 .

[20]  Horst H. Berger,et al.  Models for contacts to planar devices , 1972 .

[21]  A. S. Grove.  Physics and Technology of Semiconductor Devices , 1967 .

[22]  M. Nicolet,et al.  Diffusion barriers in layered contact structures , 1981 .

[23]  M.-A. Nicolet,et al.  Diffusion barriers in thin films , 1978 .

[24]  M. Wittmer,et al.  Electrical characteristics of TiN contacts to N silicon , 1981 .

[25]  G. Mcguire,et al.  Application of Ti: W barrier metallization for integrated circuits , 1978 .

[26]  M. Wittmer.  TiN and TaN as diffusion barriers in metallizations to silicon semiconductor devices , 1980 .

[27]  N. Cheung,et al.  Thermal stability of titanium nitride for shallow junction solar cell contacts , 1981 .

[28]  G. Y. Robinson,et al.  Study of Al/Pd2Si contacts on Si , 1977 .

[29]  M.-A. Nicolet,et al.  Studies of the Ti‐W Metallization System on Si , 1976 .

[30]  M. P. Lepselter.  Beam-lead technology , 1966 .

[31]  J. O. Mccaldin,et al.  Solid-phase epitaxial growth of Si mesas from Al metallization , 1973 .

[32]  M. Nicolet,et al.  Electrical characteristics of Al contact to NiSi using thin W layer as a barrier , 1981 .

[33]  A. S. Grove,et al.  Redistribution of Acceptor and Donor Impurities during Thermal Oxidation of Silicon , 1964 .