Accession Number : ADA293618

Title :   Contactless Characterization of Semiconductors Using Laser-Induced Surface Photo-Charge Voltage Measurements.

Descriptive Note : Final rept.

Corporate Author : ARMY ARMAMENT RESEARCH DEVELOPMENT AND ENGINEERING CENTER WATERVLIET NY BENET LABS

Personal Author(s) : Abbate, A. ; Rencibia, R. ; Ivanov, O. ; Masini, G. ; Palma, F.

PDF Url : ADA293618

Report Date : JAN 1995

Pagination or Media Count : 16

Abstract : A new technique to evaluate the electrical properties of semiconductor wafers and devices using surface photo-charge voltage (SPCV) measurements is presented. SPCV measures the change in the surface electrical charge induced by a chopped laser light whose photon energy exceeds the band gap energy of the semiconductor sample. This charge is measured capacitatively, thus SPCV measurements do not require the fabrication of metal contacts. In photocharge voltage spectroscopy measurements, the SPCV is measured as a function of the energy of a subband gap monochromatic steady-state illumination, and its derivative spectrum is associated with the density of surface states. A qualitative analysis of the proposed measurement is presented along with experimental results performed on gallium arsenide samples passivated with a thin zinc selenide film of variable thickness. The proposed technique is completely contactless, and it can be used as an in-line nondestructive characterization of semiconductor wafers during the various stages of integrated circuits fabrication. jg

Descriptors :   *VOLTAGE, *INTEGRATED CIRCUITS, *SEMICONDUCTORS, *LASERS, *SURFACE PROPERTIES, STEADY STATE, DENSITY, MEASUREMENT, THICKNESS, SPECTROSCOPY, GALLIUM ARSENIDES, ENERGY, THIN FILMS, FABRICATION, ILLUMINATION, VARIABLES, SPECTRA, SAMPLING, PHOTONS, WAFERS, QUALITATIVE ANALYSIS, MONOCHROMATIC LIGHT, STATIC ELECTRICITY, ELECTRIC CHARGE, METAL CONTACTS, ZINC SELENIDES.

Subject Categories : Electrical and Electronic Equipment
      Inorganic Chemistry
      Lasers and Masers
      Atomic and Molecular Physics and Spectroscopy
      Optics
      Solid State Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE