Electronics and Telecommunications Research Institute

Korea Telecom

Eung Gie Oh

Jae Jin Lee

Sung Weon Kang

Jae Kyoung Mun

Kwang Eui Pyun

Min Gun Kim

Jeon Wook Yang

A microwave frequency converting receiver of an RF unit should be generally used in wireless/mobile communications systems such as cellular, PCS, WLL and IMT2000 systems and also have low power consumption, low-noise characteristic, high gain and small size. In order to produce the above frequency converting receiver, a multi-band and multi-mode frequency converting receiver for use in a wireless mobile communications system comprises a wideband low-noise amplifier for amplifying a radio frequency input signal, a frequency mixer for generating an intermediate frequency signal having a relatively high linearity by mixing a local oscillator frequency signal and the amplified radio frequency signal outputted from the wideband low noise amplifier, an intermediate frequency amplifier for producing a final intermediate frequency signal by amplifying the intermediate frequency signal derived from the frequency mixer and an input matching circuit for receiving a microwave signal within a frequency band of the wireless mobile communications system, impedance-matching the received microwave signal to the radio frequency input signal of the wideband low-noise amplifier and determining an operating frequency band of the frequency converting receiver.

Microwave frequency converting receiver

Disclosed is a method for manufacturing a vertical channel transistor comprising the steps of: selectively implanting a dopant of high concentration into a semiconductor substrate to form a source region; firstly etching the semiconductor substrate using an insulator and a first photoresist pattern as a mask; secondly etching the substrate using a second photoresist pattern having a shape corresponding to said source region as a mask; implanting a dopant of low concentration into the exposed substrate using said second photoresist pattern as a mask to form a vertical channel layer; implanting a dopant of high concentration into the exposed substrate using same mask to form a drain region; activating said dopants, and forming an ohmic contact layer on said drain region; thirdly etching using a third photoresist pattern for exposing the firstly etched portion of the substrate as a mask; depositing a gate metal on the substrate exposed by the thirdly etching; and wiring a metal, respectively. This invention can be easily manufactured a vertical channel transistor having a low parasitic resistance and an extremely small gate length without sophicated complex processes.

Fabrication method of a vertical channel transistor

Growing community of inventors

Daejeon, South Korea

Eung Gie Oh