Abstract: A method and apparatus for controlling the growth of a multispecies film. During the film growth, an ellipsometer continuously monitors the surface on which the film is growing. The ellipsometer data is used to calculate the effective complex dielectric constant of the thin-film/substrate structure. A sequence of such data is used in a model calculation to determine the composition of the top portion of the thin film. The measured composition is compared with the target composition and the amount supplied of one of the species is correspondingly changed.

Abstract: A method and apparatus for epitaxial growth of precisely one monolayer. The growth is by organometallic chemical vapor deposition in which the substrate is alternately exposed to the anion and cation of a III-V compound. During deposition of the cation, for instance Ga or Al, reflectance difference spectroscopy is performed to obtain the difference of reflected light beams polarized in orthogonal directions. A growth of a monolayer and even of a partial monolayer can be monitored in real time.

Abstract: A tunable monochromator having variable groove spacing whereby each wavelength is diffracted to the same point and which is tuned by translating the grating parallel to a rotational symmetry axis is disclosed.

Abstract: A method of treating semiconductor surfaces to produce an abrupt dielectric discontinuity between the semiconductor bulk and the ambient is described.

Abstract: Layers of controllably dopable amorphous silicon and germanium can be produced by means of low pressure chemical vapor deposition, at a reaction temperature between about 450.degree. C. and about 630.degree. C., for Si, and between about 350.degree. C. and about 400.degree. C. for Ge, in an atmosphere comprising a Si-yielding or Ge-yielding precursor such as SiH.sub.4 or GeI.sub.4, at a pressure between about 0.05 Torr and about 0.7 Torr, preferably between about 0.2 and 0.4 Torr. For undoped Si and P-doped Si, the preferred temperature range is from about 550.degree. C. to about 630.degree. C., for B-doped Si, it is from about 480.degree. C. to about 540.degree. C. The material produced has a density in excess of 0.9 of the corresponding crystalline density, and contains less than 1 atomic percent of hydrogen. An advantageous doping method is addition of dopant-forming precursor, e.g., PH.sub.3 or B.sub.2 H.sub.6, to the atmosphere.

Abstract: It has been found that the dielectric function .epsilon.(.nu.) of materials is strongly dependent on the microstructure of the material, i.e., on the volume fractions that are crystalline, amorphous, and void, respectively. This sensitivity makes it possible to conveniently and nondestructively determine by optical methods, typically a form of spectroscopic ellipsometry, the microstructure of layers of material that are typically bounded by a free surface. The determination of actual volume fractions is made by fitting the result of a model calculation, typically in an effective medium approximation, to the measured dielectric function over an appropriate range of frequencies, e.g. frequencies corresponding to photon energies of approximately 1.5 eV-6 eV. Alternatively, the measured dielectric function, or selected features or functions thereof, can be compared to preselected standard values.