International Business Machines Corporation

Interface Studies Inc.

Other

John Lawrence Freeouf

Jerry M Woodall

Peter Daniel Kirchner

Thomas N Jackson

George D Pettit

David D Nolte

Rodney T Hodgson

Hans S Rupprecht

Alan B Fowler

Alan C Warren

Michael R Melloch

Jeffrey Y Tang

Steven E Laux

Norman Braslau

William J Haag

Peter Oelhafen

In this invention the technology is provided for rod shaped conductor member fabrication in situ, in position, in the mass filter spatial configuration by growth through vertically repeated conduit mold formations, filling the conduit increments with to be rod material, and coalescing the growth increments as the rod length is achieved.

Quadrupole mass filter length selection

Accuracy and sensitivity in the optical characterization of solids and solid materials are improved through the use of the interdependent features of: extending the photon energy range over which the metrology is performed to include a portion of the range up through 10 eV, in which, the higher photon energy of the light improves signal distinguishing ability; and providing a controlled ambient in the entire light path between the light source and a detector that prevents absorption and signal definiteness masking so as to sharpen the identifiability of the change parameters imparted into the reflected light. Combinations of specific devices and materials that for different types of ellipsometry are provided.

High photon energy range reflected light characterization of solids

Improvements in accuracy and sensitivity in mechanical-optical metrology apparatus are achieved through the use of a value for angle of incidence that is an average of positive and negative values for different arrangements of the metrology apparatus. In the ellipsometry type of metrology the average value for angle of incidence is established by using one of a reversal of light beam direction, the providing of a separate light beam mounting arm and the mechanical rotation of the sample.

Angle of incidence accuracy in ultrathin dielectric layer ellipsometry measurement

Metrology for ultrathin dielectric layers of the order of less than 10 nanometers in thickness is achieved by specular ellipsometry in a totally controlled ambient between the light source and the detector, in which, a precise 2.75 through 9.0 eV photon energy range continuum of light is employed. In the signal analysis there is the taking into consideration the effect of noise in the development of the ellipsometric parameter values and in the resulting data. In the invention the precise photon energy range operates to sharpen the identifiability of the change parameters imparted into the reflected light in the ellipsometry while minimizing absorption and signal definiteness masking; and the taking into consideration of noise in the signal analysis involves providing a simulated noise spectrum for comparison with the least squares fitting algorithm-derived parameters to determine the quality of the minimum and the reliability of the inferred parameters.

Ultrathin layer measurement having a controlled ambient of light path

A radiation detection structural principle for improved detection wherein absorbtion members of high density and bandgap semiconductor material and meeting all efficiency limiting requirements are provided with a sweeping field applied across each member. The absorbtion members are assembled in stack structures for particular energy resolution benefits. The detector principle is extendable to long absorbtion paths and to energy resolution in specific areas.

Solid state radiation detector

A radiated energy to electrical energy conversion device and technology is provided where there is a single absorber layer of semiconductor material. The thickness of the absorber layer is much less than had been appreciated as being useful heretofore in the art. Between opposing faces the layer is about &frac12; or less of the carrier diffusion length of the semiconductor material which is about 0.02 to 0.5 micrometers. The thickness of the absorber layer is selected for maximum electrical signal extraction efficiency and may also be selected to accommodate diffusion length damage over time by external radiation.

Fabrication of single absorber layer radiated energy conversion device

A radiated energy to electrical energy conversion device and technology is provided where there is a single absorber layer of semiconductor material. The thickness of the absorber layer is much less than had been appreciated as being useful heretofore in the art. Between opposing faces the layer is about 1/2 or less of the carrier diffusion length of the semiconductor material which is about 0.02 to 0.5 micrometers. The thickness of the absorber layer is selected for maximum electrical signal extraction efficiency and may also be selected to accommodate diffusion length damage over time by external radiation.

Single absorber layer radiated energy conversion device

A light responsive device (10) has a body (12) that includes a matrix comprised of Group III-V material, the matrix having inclusions (14) comprised of a Group V material contained therein. The body is responsive to a presence of a light beam that has a spatially varying intensity for modifying in a corresponding spatially varying manner a distribution of trapped photoexcited charge carriers within the body. The distribution of trapped charge carriers induces a corresponding spatial variation in at least one optical property of the Group III-V material, such as the index of refraction of the Group III-V material and/or an absorption coefficient of the Group III-V material. The Group III-V material is comprised of LTG GaAs:As or LTG AlGaAs:As. In an optical storage medium embodiment of the invention the spatial variation in the intensity of the light beam results from a simultaneous application of a first light beam (LB1) and a second light beam (LB2) to the body, and from interference fringes resulting from an intersection of said first and second light beams.

LTG AlGaAs non-linear optical material and devices fabricated therefrom

A semiconductor device where an emitter material composition and doping profile produces an electron gas in a base adjacent a band offset heterojunction interface, the electrons in the electron gas in the base are confined under bias by a low barrier and the ballistic carriers have their kinetic energy controlled to prevent intervalley scattering by an electrostatic barrier that under influence of bias provides an essentially level conduction band in the portion of the base adjacent the collector.

Semiconductor ballistic electron velocity control structure

A surface termination of a compound semiconductor is provided wherein conditions are provided for a pristine surface to be retained in an unpinned condition and a surface layer of a non-metallic material is provided. A GaAs substrate is heated in an oxygen-free atmosphere at high temperature with hydrogen sulfide, producing a pristine surface with a coating of gallium sulfide covered with a 1,000 nanometer covering of low temperature plasma enhanced chemical vapor deposited silicon dioxide.

Compound semiconductor surface termination

An electrical device which employs two-dimensional space charge modulation in a semiconductor structure. The device has an approximately Debye length wide contact and a rectifying contact positioned adjacent to each other within a Debye length on a semiconductor body and a contact remotely positioned. A bias on the rectifying contact will effect conduction between the other contacts.

Space charge modulation device

Crystalline compound semiconductors are passivated with a layer of the most volatile element thereof to prevent the formation of oxides that would interfere with further processing. A GaAs crystal is provided with a surface layer of arsenic. The arsenic layer is formed by exposure to light having a photon energy greater than 1.8 eV, at a power density of 0.01 to 0.5 watts per cm.sup.2 while the GaAs immersed in a 1:1 HCl:H.sub.2 O solution for a period of 10-30 minutes. The intermediate processing passivated GaAs crystal may be stored and handled in air and the As layer is removed by low temperature baking.

Intermediate passivation and cleaning of compound semiconductor surfaces

In a molecular beam epitaxy furnace, a heater is described for heating the interior of an effusion cell. The heater includes an outer cylindrical sleeve having one end connected to receive a vacuum, and an opposite end extending into the furnace. An inner sleeve is provided coaxial with the outer cylindrical sleeve, one end of the inner sleeve being sealed with the opposite end of the cylindrical sleeve. The inner sleeve extends along a portion of the outer cylindrical sleeve providing an interior vacuum chamber. A heating element is disposed between the cylindrical sleeve and inner sleeve which heats the interior crucible receiving chamber and a crucible therein bearing semiconductor constituent material such that the semiconductor constituent material effuses without contamination from the heating element.

Heater assembly for molecular beam epitaxy furnace

A refractory compound structure comprising a substrate of a compound which is a combination of a refractory and/or metallic element and a nonmetallic element and an elemental layer of the refractory and/or metallic element on the substrate is formed by heating the refractory compound in a vacuum at a decomposition temperature for the refractory compound.

Refractory structure and process for the preparation thereof

When growing GaAs by molecular beam epitaxy (MBE), a typical related reaction acts to affix Ga.sub.2 O.sub.3 to the growth surface and hence incorporates such oxide contaminants in the epitaxial layer as it is grown. Such contaminants may yield crystals of poor electrical and optical properties. When Al is added to the Ga source crucible, the Ga.sub.2 O flux is reduced substantially thereby suppressing the formation of such oxide contaminants and remove a serious constraint to MBE growth. When doping GaAs with Mg to form a p-type GaAs layer, unity Mg doping efficiency is achieved by including 0.1% Al in the Ga effusion cell. Such an inclusion of Al improves the Mg doping efficiency by suppressing the formation of MgO, and allows MBE growth at lower substrate temperatures and at higher growth rates.

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Katonah, NY, United States of America

John Lawrence Freeouf