Abstract:
The present invention is related to a bipolar transistor in which the in-situ doped epitaxial Si or SiGe base layer is used instead of using an ion-implanted Si base, in order to achieve higher cutoff frequency. The SiGe base having the narrower energy bandgap than the Si emitter allows to enhance the current gain, the cutoff frequency (fT), and the maximum oscillation frequency (fmax). The narrow bandgap SiGe base also allows to have higher base doping concentration. As a result, the intrinsic base resistance is lowered and the noise figure is thus lowered. Parasitic base resistance is also minimized by using a metallic silicide base ohmic electrode. The present invention is focused on low cost, high repeatability and reliability by simplifying the manufacturing process step.
Abstract:
The invention relates to a method for manufacturing a super self-aligned heterojunction bipolar transistor which is capable of miniaturizing an element, simplifying the process step thereof by employing a selective collector epitaxial growth process without using a trench for isolating between elements. According to the invention, isolation between elements is derived by using a mask defining an emitter region and a second spacer. The base layer has multi-layer structure being made of a Si, an undoped SiGe, a SiGe doped a p-type impurity in-situ and Si. Also, the selective epitaxial growth for a base is not required. Thus, it can be less prone to a flow of leakage current or an emitter-base-collector short effect.
Abstract:
Disclosed is a device isolating method of a semiconductor device, comprising the steps of sequentially forming a pad oxide film, a polysilicon film and an insulating layer, on a silicon substrate, said insulating layer being composed of a first silicon oxide film, a nitride film and a second silicon oxide film formed sequentially on the polysilicon film; defining active and inactive regions by using a patterned photomask; removing the insulating layer only on the inactive region so as to expose a surface of the polysilicon film; forming a side wall at both edges of the insulating layer on the active region, said side wall being composed of a nitride film; depositing a third silicon oxide film on the surface of the polysilicon film; removing the side wall and etching the substrate to a predetermined depth to form a trench; filling an insulating material into the trench and depositing it up to the second silicon oxide so as to form an insulating film for isolating; simultaneously removing the second silicon oxide film and the silicon oxide film and removing the polysilicon film only the inactive region; performing a thermal oxidation to form a field oxide film on the inactive region; and sequentially removing the isolating layer and the polysilicon film formed on the active region. Because the active region is defined using an insulator-filled shallow trench before performing thermal oxidation, no oxygen is penetrated into the active region during the thermal oxidation, whereby a field oxide film can be formed without occurrence of a Bird's beak.
Abstract:
A silicon/silicon-germanium bipolar transistor fabrication method employs a metallic silicide film as an extrinsic base electrode to reduce resistance of the extrinsic base electrode, and to increase a maximum oscillation frequency and cut-off frequency due to its self-aligned structure. The fabrication method enables agglomeration to occur on the side wall of the polycrystalline silicon film connected to the metallic silicide film instead of on the interface between the metallic silicide film and the lower silicon/silicon-germanium film, and leads the extrinsic base electrode to be sandwitched by the insulator films, thereby realizing a constant resistance and also resulting in the application of integrated circuits to a mass production mechanism.
Abstract:
There is provided a nitride semiconductor device including: an n-type nitride semiconductor layer; a p-type nitride semiconductor layer; and an active layer formed between the n-type and p-type nitride semiconductor layers, the active layer including a plurality of quantum well layers and at least one quantum barrier layer deposited alternately with each other, wherein the active layer includes a first quantum well layer, a second quantum well layer formed adjacent to the first quantum well layer toward the p-type nitride semiconductor layer and having a quantum level higher than a quantum level of the first quantum well layer, and a tunneling quantum barrier layer formed between the first and second quantum well layers and having a thickness enabling a carrier to be tunneled therethrough.
Abstract:
A nitride semiconductor single crystal substrate, a manufacturing method thereof and a method for manufacturing a vertical nitride semiconductor device using the same. According to an aspect of the invention, in the nitride semiconductor single crystal substrate, upper and lower regions are divided along a thickness direction, the nitride single crystal substrate having a thickness of at least 100 μm. Here, the upper region has a doping concentration that is five times or greater than that of the lower region. Preferably, a top surface of the substrate in the upper region has Ga polarity. Also, according to a specific embodiment of the invention, the lower region is intentionally un-doped and the upper region is n-doped. Preferably, each of the upper and lower regions has a doping concentration substantially identical in a thickness direction.
Abstract:
There is provided a nitride semiconductor light emitting device. A nitride semiconductor light emitting device according to an aspect of the invention may include: an n-type nitride semiconductor layer provided on a substrate; an active layer provided on the n-type nitride semiconductor layer, and including quantum barrier layers and quantum well layers; and a p-type nitride semiconductor layer provided on the active layer, wherein each of the quantum barrier layers includes a plurality of InxGa(1-x)N layers (0
Abstract translation:提供了一种氮化物半导体发光器件。 根据本发明的一个方面的氮化物半导体发光器件可以包括:设置在衬底上的n型氮化物半导体层; 设置在n型氮化物半导体层上的有源层,并且包括量子势垒层和量子阱层; 以及设置在有源层上的p型氮化物半导体层,其中每个量子势垒层包括多个In x Ga(1-x)N层(0
Abstract:
A nitride semiconductor device according to an aspect of the invention may include: first and second conductive nitride semiconductor layers; and an active layer having a DH structure located between the first and second conductive nitride semiconductor layers, and including a single quantum well structure active layer having the single quantum well structure includes at least one polarization relaxation layer formed of a nitride single crystal having a higher energy band gap than the quantum well.
Abstract:
A method of growing a III group nitride single crystal by using a metal-organic chemical vapor deposition (MOCVD) process, the method including: preparing an r-plane (1-102) substrate; forming a nitride-based nucleation layer on the substrate; and growing a nonpolar a-plane nitride gallium single crystal on the nitride-based nucleation layer while altering increase and decrease of a ratio of V/III group to alternate a horizontal growth mode and a vertical growth mode.