Accession Number : ADA317084

Title :   Stable Contacts to Semiconductors.

Descriptive Note : Final rept. 1 Apr 92-30 Sep 95,

Corporate Author : CALIFORNIA INST OF TECH PASADENA

Personal Author(s) : Nicolet, Marc A.

PDF Url : ADA317084

Report Date : SEP 1996

Pagination or Media Count : 6

Abstract : By extending our previous investigations of the ternary thin-film barriers of Ta-Si-N to Mo-Si-N and W-Si-N, we have confirmed that the reason for the success of these thin-film barrier layers between Si and Cu rests on two basic features: (1) their thermodynamic stability with Cu, and (2) their amorphous (or near-amorphous) structure. The dependence of the electrical resistivity of these layers on the nitrogen composition further proves that at the atomic level, local order exists that concurs with that of the equilibrium phases. Structural investigations including small-angle x-ray scattering and high resolution transmission electron diffraction have established beyond doubt that the alloys, as they are formed by our reactive spattering process, are amorphous over large ranges of composition. Differences between the stability of various transition metal (Tm)-Si-N alloys can be attributed to the variation of the strength with which nitrogen is bonded in the alloy. The barriers have been successfully applied to enhance the stability of n(+)p shallow silicon junction diodes with a Cu metallization, as to suppress the diffusion of Cu into SiO2. A very complete investigation of Ti-Si-N has been initiated because this alloy has the best chance of being accepted by the industry, TiN being already an industry standard for thin-film diffusion barrier applications.

Descriptors :   *STABILITY, *THIN FILMS, *SEMICONDUCTORS, *BARRIERS, TRANSITION METALS, LAYERS, THERMODYNAMICS, MOLYBDENUM, EQUILIBRIUM(GENERAL), ALLOYS, NITROGEN, VARIATIONS, COPPER, SILICON, STRENGTH(GENERAL), X RAY SCATTERING, ELECTRICAL RESISTANCE, DIFFUSION, TERNARY COMPOUNDS, TANTALUM, TUNGSTEN, ATOMIC ENERGY LEVELS.

Subject Categories : Inorganic Chemistry
      Electrical and Electronic Equipment
      Physical Chemistry
      Properties of Metals and Alloys
      Atomic and Molecular Physics and Spectroscopy

Distribution Statement : APPROVED FOR PUBLIC RELEASE