摘要:
The structure presented herein provides a base structure for semiconductor devices, in particular for III-V semiconductor devices or for a combination of III-V and Group IV semiconductor devices. The fabrication method for a base substrate comprises a buffer layer, a nucleation layer, a Group IV substrate and possibly a dopant layer. There are, in a general aspect, two growth steps: firstly the growth of a lattice-matched III-V material on a Group IV substrate, followed by secondly the growth of a lattice-mismatched III-V layer. The first layer, called the nucleation layer, is lattice-matched or closely lattice-matched to the Group IV substrate while the following layer, the buffer layer, deposited on top of the nucleation layer, is lattice-mismatched to the nucleation layer. The nucleation layer can further be used as a dopant source to the Group IV substrate, creating a p-n junction in the substrate through diffusion. Alternatively a separate dopant layer may be introduced.
摘要:
The present invention relates to a system and method for generating high efficiency silicon-based photovoltaic cells such as solar cells. The solar cell of the present invention comprises a silicon substrate layer, a first buffer layer disposed on a first surface of the silicon substrate layer and a second buffer layer disposed on the opposing surface of the silicon substrate layer and a third buffer layer disposed directly on the first buffer layer, the first and second buffer layers being lattice mismatched to the silicon substrate layer, and a first device layer disposed on the third buffer layer and a second device layer disposed on the second buffer layer, the first and second device layers comprising at least one of Sb-based compounds, III-V compounds and II-VI compo
摘要:
In an imaging system for carrier profiling of a device structure, a doped semiconductor tip is utilized as an active dynamic sensing element for successively probing spaced-apart portions of the structure. At each probe position, the bias voltage applied between the tip and the structure is varied. While the bias voltage is being varied, a measurement is taken of the change in capacitance that occurs between the tip and the structure. These measurements provide an accurate high-resolution high-contrast image that is representative of the carrier profile of the probed portions of the device structure.
摘要:
This invention relates to a method and apparatus for imaging acoustic fields in high-frequency acoustic resonators. More particularly, the invention is directed to a scanning RF mode microscope system that detects and monitors vibration of high frequency resonators that vibrate in the frequency range of approximately 1 MHz to 20 GHz. The system then maps with sub-Angstrom resolution vibration modes of such devices and obtains quantitative measurements of the piezoelectric properties of the materials.
摘要:
A piezoelectric micropositioning device includes, in one embodiment, four single-crystal piezoelectric bodies cut in the form of single-crystal parallel slabs from a single larger single crystal. Each of the single-crystal slabs has a separate electrode attached to an opposing major surface. One of the end faces of each of the slabs is fixed to a substrate; the other of the end faces is fixed to a holder. In response to voltages applied to the electrodes, the holder can be moved in two or three linearly independent directions, depending upon the applied voltages. In another embodiment, only a single piezoelectric body, preferably in the shape of a column and in conjunction with at least four electrodes located on the side surfaces of the column, is required for such motion in two or three directions.
摘要:
A method and geometry for reducing drift in an electrostatically actuated device, the electrostatically actuated device including a dielectric material, for insulating conducting sections from a ground, the conducting sections being used to generate an electric field for controlling thereby the electrostatically actuated device includes, configuring a geometry of the dielectric material such that the electric field applied to exposed dielectric material comprises a substantially homogeneous electric field.
摘要:
An electro-optic device comprising an electro-optic crystal substrate, an optical waveguide path in the crystal adjacent the substrate surface and an electrode spaced from the surface by a buffer layer is provided with enhanced operating stability by forming the buffer layer of a transparent electronically conductive material. Preferred buffer materials are electronically conductive gallium-indium-oxide and electronically conductive zinc-indium-tin-oxide.