Abstract:
PURPOSE: A semiconductor device and a forming method thereof are provided to improve the low noise property by reducing the parasitic capacitance among the gate electrode, the source electrode, and the drain electrode. CONSTITUTION: An active layer is formed on the top of the substrate. The capping layer is formed on the active layer. A source and a drain electrode are formed on the capping layer. A gate electrode(140) is formed on the active layer. A first void region(155) is formed on the first side wall of the gate electrode. A second void region(156) is formed on the second side wall facing the first side wall.
Abstract:
PURPOSE: A method for manufacturing a pseudomorphic high electron mobility transistor device is provided to satisfy wideband characteristics and unconditionally stable conditions by including a negative feedback circuit. CONSTITUTION: In a method for manufacturing a pseudomorphic high electron mobility transistor device, an epitaxial substrate is provided(101). A source and a drain are formed on a substrate. The epitaxial substrate is processed by a gate recess etching including a dry and wet method to form a recess region. The gate(180) is formed in the recess region.
Abstract:
PURPOSE: A super high frequency amplifier and a bias circuit for the same are provided to optimize performance by adjusting a source voltage, regardless of a change in the properties of a depletion-type FET(Field Effect Transistor) due to the process change. CONSTITUTION: An amplifier circuit amplifies a high frequency signal through a depletion-type FET(30). An input matching circuit(20) matches the inputted high frequency signal in the depletion-type FET. An output matching circuit(40) matches the amplified signal, and thereby outputs the matched signal. A bias circuit(80) gives a negative value to a voltage between a gate and a source of the depletion-type FET by applying a positive voltage to the source of the depletion-type FET. The bias circuit tunes the voltage between the gate and the source by changing the positive voltage applied to the source.
Abstract:
A UHF(Ultra High Frequency) amplifier is provided to minimize variation of a capacitance due to variation of a manufacturing condition by maintaining a constant capacitance irrespective of a thickness variation of a dielectric material. An amplifier amplifies a high frequency signal. Input matching circuits(110,130) match the high frequency signals from input terminals with each other and supply the matched signals to the amplifier. Bias supply units(150,160,170,180) supply bias voltages to the amplifier. Output matching circuits(120,135) deliver the high frequency signal amplified at the amplifier to an output terminal. A DC block/RF(Radio Frequency) matching unit(101,126,136) is coupled between the input terminal and the input matching circuit or between the output matching circuit and the output terminal, and is configured to have first and second strip lines having a spiral or curved shape.
Abstract:
A gold bump structure which can reduce defective proportion generated due to causes such as lead opening and the like in a process of bonding the gold bump to semiconductor chips and so on by improving non-uniformity of the gold bump with respect to thickness of a gold bump formed by a plating process, and a fabrication method of the gold bump structure are provided. A gold bump comprises: a seed metal layer formed on a substrate; a plating bump layer formed on an upper portion of the seed metal layer; and a domed gold-rich process alloy formed on an upper portion of the plating bump layer and made from a metal with a low melting point. A fabrication method of a gold bump comprises the steps of: forming a seed metal layer(23) on a substrate(21); plating and forming a gold bump layer(25) on the seed metal layer; forming a metal layer with a low melting point on the gold bump layer; and forming a domed gold-rich process alloy(27) on an upper portion of the low melting point metal layer-formed gold bump layer. The method further comprises the steps of: forming an adhesion layer(22) between the seed metal layer and the substrate; removing the exposed seed metal layer and the adhesion layer under the exposed seed metal layer; and forming a photosensitive film for forming patterns of the gold bump layer.
Abstract:
A method for manufacturing a pseudo morphic high electro mobility transistor is provided to improve the electric property and to increase breakdown voltage by forming a passivation layer having double recess structure. A cap layer(24) and a channel layer(22) are formed on a substrate(20). A source/drain(26) is formed on the cap layer. A first passivation layer(27) is formed, and then patterned to expose the cap layer in a channel region. A first recess structure is formed by removing the exposed cap layer. A second passivation layer is formed on the entire surface of the resultant structure. A second recess structure is formed by patterning the second passivation layer(29) to expose the substrate of the first recess structure. A multi-layered photosensitive film is formed, and then patterned to have an opening of gate shape and to expose the substrate through the second recess structure. A gate is formed to connect to the substrate through the second recess structure by removing the multi-layered photosensitive film, after depositing a metal on the resultant structure.
Abstract:
본 발명은 안정화 회로가 구비된 고주파 증폭기에 관한 것으로, 보다 상세하게는 소정의 고주파 신호를 증폭하기 위한 트랜지스터를 포함하는 고주파 증폭기에 있어서, 상기 트랜지스터의 입력단에 입력된 고주파 신호의 이득 손실을 방지함과 아울러 이득 안정도를 증가시키기 위한 저항과 캐패시터가 병렬로 구성된 안정화 회로가 직렬로 연결됨으로써, 고주파 증폭기의 이득 손실 없이 안정도를 향상시킬 수 있는 효과가 있다. 고주파 증폭기, 안정화 회로, 저항, 캐패시터, 임피던스, 트랜지스터, 입력 임피던스 정합부, 출력 임피던스 정합부, 바이어스 회로부