Korea Advanced Institute of Science and Technology

Young Se Kwon

Tae Kyung Yoo

Kyoung Hoon Yang

Bun-Joong Kim

Seong Ho Shin

Ju Hyun Ko

Soo Kun Jeon

Jung Ho Cha

Moon Jung Kim

Disclosed herein are a transmission line of coaxial type and a manufacturing method thereof, capable of preventing a radiative signal loss of signal lines during transmission of an RF signal and removing signal interference between adjacent signal lines, thus allowing signal lines to be compactly arrayed during a manufacture of IC, and reducing a dimension of the IC. The transmission line of coaxial type includes grooves provided on a semiconductor substrate, a first ground layer, an electrically conductive epoxy coated on a flat part of the first ground layer except the grooves, second ground layers provided on the electrically conductive epoxy, a dielectric film provided at a position above the grooves and the second ground layers, a third ground layer provided on an upper surface of the dielectric film, and signal lines placed in spaces defined by the grooves and a lower surface of the dielectric film. In this case, the electrically conductive epoxy is coated on only contact surfaces of the first and second ground layers, and the signal lines are attached to the lower surface of the dielectric film.

Grooved coaxial-type transmission line, manufacturing method and packaging method thereof

Disclosed is a method of manufacturing a photoreceiver, including sequentially laminating a buffer layer, a channel layer, a barrier layer, and a cap layer on a substrate; forming a mesa for HEMT and MSM PD by removing the buffer layer, the channel layer, the barrier layer, and the cap layer with the exception of a region corresponding to HEMT and MSM PD; forming a source electrode and a drain electrode of HEMT; removing the cap layer from a region corresponding to a gate electrode of HEMT and a Schottky electrode of MSM PD; forming the gate electrode of HEMT and the Schottky electrode of HEMT on the cap layer-removed region; and removing the cap layer, the barrier layer and the channel layer from a region corresponding to an optical waveguide, to expose the optical waveguide.

Method of manufacturing photoreceiver

The present invention relates to an optical coupling module for optically coupling an optical fiber with an optical waveguide, and a method of fabricating the optical coupling module. In an optical coupling module for optically coupling an optical network with a planar lightwave circuit (PLC), an etched groove for disposition of the optical fiber and an etched groove for mounting of the optical waveguide are exposed using a mask having mask patterns that are aligned with each other, and then anisotropically etched. By doing so, the two grooves can be precisely aligned with each other at one time, compared with a conventional method in which an exposure process is carried out two or more times. Accordingly, an inexpensive structure having high optical coupling efficiency upon manual alignment can be obtained. In addition, since a tapered structure in which an inlet is larger than a body is employed in the optical waveguide, tolerance in vertical and horizontal alignment upon manual alignment can be broaden, resulting in improvement of optical coupling efficiency and facilitation of manual alignment. Furthermore, by utilizing a thick insulation film on the substrate or a thick insulation film of the optical waveguide itself as a board, a structure for allowing assembly into and application to a high-frequency electric-optical circuit can be obtained.

Optical coupling module with self-aligned etched grooves and method for fabricating the same

Disclosed is a method for fabricating a self-aligned submicron gate electrode using an anisotropic etching process. The method involves the steps of laminating a dummy emitter defining a dummy emitter region over a heterojunction bipolar transistor structure including layers sequentially formed over a semiconductor substrate to define a base region, an emitter region, and an emitter cap region, respectively, defining a line having a width of about 1 micron on the dummy emitter by use of a photoresist while using a contact aligner, selectively anisotropic etching the dummy emitter at a region where the line is defined, to allow the dummy emitter to have an etched portion having a bottom surface with a width less than the width of the line defined by the photoresist, and depositing a contact metal on the etched portion of the dummy emitter, thereby forming a gate. In accordance with the present invention, a reliable submicron gate can be fabricated using a simple anisotropic wet etch process and an inexpensive contact aligner. Accordingly, the manufacturing costs can be reduced. In the formation of a base electrode involved in the fabrication of an HBT device, the present invention also provides an effect of reducing the distance between a base and an emitter, thereby achieving a reduction in base resistance, by virtue of a self-alignment using a V-shaped submicron gate.

Fabrication method of submicron gate using anisotropic etching

A method for manufacturing a surface emitting type AlGaAs/GaAs semiconductor LASER diode by a selective epitaxy method which is capable of forming naturally a 45.degree. mirror reflective face during the epitaxy method itself. The method comprises the steps of forming a silicon oxide or silicon nitride layer on one side of a n-type single crystal GaAs substrate as a mask, removing the mask of the regions each for forming a 45.degree. mirror reflective face and a LASER diode by use of a photolithography and a chemicaletching, forming the two layers by removing the photoresistor on the remaining mask after a selective epitaxy process and converting a slant face of the LASER diode into a vertical face, depositing a n-type metal layer on the other side of the substrate, and carrying out a heat treatment.

Growing community of inventors

Daejeon, South Korea

Young Se Kwon