Abstract:
본 발명은 T형 게이트 전극의 형성방법에 관한 것으로서, 반도체 기판 상의 소정 부분에 미세 게이트 금속을 형성하고, 반도체 기판 및 미세 게이트 금속상에 절연막과 평탄화막을 형성한 후 절연막이 노출되도록 평탄화막을 에치백하고, 절연막의 노출된 부분을 등방성으로 식각하여 평탄화막의 역경사를 이루는 측면을 노출시키고 저저항금속을 방향성을 갖도록 증착한다. 따라서, 광학적 기소그라피 공정으로 쉽게 T-형상의 게이트를 형성할 수 있으므로 생산성을 향상시킬 수 있으며, 미세 게이트 패턴 상에 중첩되는 저저항금속을 자기 정렬되게 형성할 수 있다.
Abstract:
PURPOSE: An electric optical polymer for a wavelength division multiplexing optical communication network, a high speed tunable selecting filter using multi-grating and their operating method are provided to enable implementation of a dense wavelength division multiplexing based optical communication and be used for an optical information storing device technique utilizing an optical refraction. CONSTITUTION: An optical waveguide(103) collects a plurality of lights made incident to a single mode. A Bragg grating unit passes only a light of a desired wavelength among the plurality of lights made incident along the optical waveguide(103) and reflects the remaining lights along the optical waveguide(103) to emit them externally. A proceeding waveform electrode(105) changes a region of a Bragg grating reflection wave by an electro-optical effect and transmits or reflects a specific wavelength selectively. A TEC(106) tunes the wavelength of the whole bragg reflection wave by using a heat optical effect of a polymer.
Abstract:
PURPOSE: A method for fabricating a progressive wave coplanar electrode of a high speed polymer mach-gender optical modulator is to simplify a design of an electrode and reduce a DC-drift and an operating voltage. CONSTITUTION: A high speed polymer optical modulator having a progressive wave coplanar electrode comprises a channel light guide(1), a progressive coplanar electrode(3), an incline plane(2) and an input/output unit. The progressive wave coplanar electrode is formed by etching the channel light guide in order to increase an overlap constant of an electric field and a guide mode. The coplanar electrodes(6,9) are crossed over the incline plane. The input/output unit inputs/outputs a microwave through a coupler having a coplanar structure. The light guide is implemented with a mach-gender interferometer. A mode of the light guide is identical to that of an optical fiber.
Abstract:
PURPOSE: An electric optical polymer for a wavelength division multiplexing optical communication network, a high speed tunable selecting filter using multi-grating and their operating method are provided to enable implementation of a dense wavelength division multiplexing based optical communication and be used for an optical information storing device technique utilizing an optical refraction. CONSTITUTION: An optical waveguide(103) collects a plurality of lights made incident to a single mode. A Bragg grating unit passes only a light of a desired wavelength among the plurality of lights made incident along the optical waveguide(103) and reflects the remaining lights along the optical waveguide(103) to emit them externally. A proceeding waveform electrode(105) changes a region of a Bragg grating reflection wave by an electro-optical effect and transmits or reflects a specific wavelength selectively. A TEC(106) tunes the wavelength of the whole bragg reflection wave by using a heat optical effect of a polymer.
Abstract:
PURPOSE: A device for detecting optical waveguide of concentrative optical type is provided to optical waveguide detect array LD(laser diode) as a next generation WDM(wavelength division multiplexing). CONSTITUTION: The device for detecting waveguide(504) is formed by a laser diode(501), a plate optical waveguide(505), and a space division multi-channel optical detector(507). The device is assembled on a thermoelement. Optical output of the laser diode is concentrated in an optical fiber(503) by a lens(502). Herein, error in transmitting center wave length of a grating optical filter(506) is attenuated by properly selecting the optical waveguide. By change in temperature to adjust optical wavelength of the laser diode, rear output of the laser diode is concentrated on the plate optical waveguide.
Abstract:
PURPOSE: A bias stabilizing circuit is provided to be capable of minimizing the current variations of amplification transistors caused by variations of device parameters which occur during the manufacturing of high-frequency integrated circuits, and caused by variations of supply voltage and temperature. CONSTITUTION: The bias stabilization circuit according to the present invention has an enhancement type reference voltage generation transistor(441) for generating a reference voltage having an amplification transistor(401), a constant current source to flow a constant current via the transistor(441) and a level shift and feedback circuit to shift voltage level of the constant current source and supply to gates of the transistors(441,401). That is, the constant current source is connected between the supply voltage Vcc and a first connection node K1, in which the constant current source has a depletion type transistor(443) and a resistor(442) connected in series thereto and the gate of the depletion type transistor(443) is connected to a node. The drain and source of the transistor(441) are connected between the first connection node and a ground. A level shift and feedback circuit is connected between a power supply and the ground and has a common drain transistor(444), resistors(445,446) which are connected to each other in series. A resistor(411) is connected between a second connection node, which is a connection node of the resistors(445,446), and the gate of the amplification transistor(401), wherein the second connection node is connected to a gate of the transistor(441). Also, the gate of the common drain transistor(444) is connected to the first connection node while a gate of the transistor(441) is connected to the second connection node.
Abstract:
PURPOSE: A method for fabricating a modified gate by a lithography and an electroplating method is provided to improve the characteristics of a device, by reducing a gate resistance by increasing a section area, and by reducing a parasitic component generated between a gate head and an ohmic layer with lengthening a leg of the gate. CONSTITUTION: An ohmic metal layer(AuGe/Ni/Au)(3) is formed after growing an active layer(2) on a compound semiconductor substrate(1). The first resist(4) for gate leg is deposited, and a gate electrode pattern is formed. The resist for gate leg is PMMA and is annealed at about 180 deg.C. And, electron beam lithography process is performed to form a narrow gate when forming a pattern. The width of the pattern is below 0.25 micrometer. Then, a base metal layer(Ti/Ni)(5) for electroplating is formed on the micro pattern. And, the second resist film(6) is deposited, and is patterned with a mask pattern of the gate head. That is, the gate head pattern is formed using a light exposure method to control a gate resistance. Then, a gold(7a,7) is electroplated on the gate metal, and then, the gate metal with a long leg and large head is formed by lifting off the resist layer.