Abstract:
Provided are image sensor having a heterojunction bipolar transistor (HBT) and a method of fabricating the same. The image sensor is fabricated by use of silicon-germanium bipolar junction transistor complementary metal oxide semiconductor (SiGe BiCMOS) technology. In the image sensor, a PD employs a floating-base-type SiGe HBT unlike a pn-junction-based CMOS image sensor (CIS). A floating base of the SiGe HBT produces a positive (+) voltage with respect to a collector during an exposure process, and the HBT performs a reverse bipolar operation due to the positive voltage so that the collector and an emitter exchange functions. In particular, since the SiGe HBT obtains a current gain ten times as high as that of a typical bipolar device even during the reverse operation, the SiGe HBT cannot only sense an optical (image) current signal but also amplify the optical current signal. Thus, the image sensor requires only three transistors in a pixel so that the degree of integration can increase. Also, the floating base of the HBT is a SiGe or SiGeC epitaxial layer with a very small thickness of 150 Å or less, and even heavily doped B ions are barely thermally diffused due to the properties of the SiGe or SiGeC layer. As a result, the sensitivity of signals can improve in the short wavelength region, thus easily balancing three colors. Furthermore, since the image sensor is a direct signal current amplification type mechanism and senses an optical signal current in a steady mode, a sensing signal has excellent linearity, and thus both a sensing mechanism and control circuit are very simple.
Abstract:
Provided is a method of fabricating a T-type gate including the steps of: forming a first photoresist layer, a blocking layer and a second photoresist layer to a predetermined thickness on a substrate, respectively; forming a body pattern of a T-type gate on the second photoresist layer and the blocking layer; exposing a predetermined portion of the second photoresist layer to form a head pattern of the T-type gate, and performing a heat treatment process to generate cross linking at a predetermined region of the second photoresist layer except for the head pattern of the T-type gate; performing an exposure process on an entire surface of the resultant structure, and then removing the exposed portion; and forming a metal layer of a predetermined thickness on an entire surface of the resultant structure, and then removing the first photoresist layer, the blocking layer, the predetermined region of the second photoresist layer in which the cross linking are generated, and the metal layer, whereby it is possible to readily perform a compound semiconductor device manufacturing process, and to reduce manufacturing cost by means of the increase of manufacturing yield and the simplification of manufacturing processes.
Abstract:
A method for fabricating a power semiconductor device having a trench gate structure is provided. An epitaxial layer of a first conductivity type having a low concentration and a body region of a second conductivity type are sequentially formed on a semiconductor substrate of the first conductivity type having a high concentration. An oxide layer pattern is formed on the body region. A first trench is formed using the oxide layer pattern as an etching mask to perforate a predetermined portion of the body region having a first thickness. A body contact region of the second conductivity type having a high concentration is formed to surround the first trench by impurity ion implantation using the oxide layer pattern as an ion implantation mask. First spacer layers are formed to cover the sidewalls of the first trench and the sidewalls of the oxide layer pattern. A second trench is formed using the oxide layer pattern and the first spacer layers as etching masks to perforate a predetermined portion of the body region having a second thickness greater than the first thickness. A source region of the first conductivity type having a high concentration is formed to surround the second trench by impurity ion implantation using the oxide layer pattern and the first spacer layers as ion implantation masks. Second spacer layers are formed to cover the sidewalls of the second trench and the sidewalls of the first spacer layers. A third trench is formed to a predetermined depth of the epitaxial layer using the oxide layer pattern, the first spacer layers, and the second spacer layers as etching masks. A gate insulating layer is formed in the third trench. A gate conductive pattern is formed in the gate insulating layer. An oxide layer is formed on the gate conductive layer pattern. The first and second spacer layers are removed. A first metal electrode layer is formed to be electrically connected to the source region and the body contact region. A second metal electrode layer is formed to be electrically connected to the gate conductive layer pattern. A third metal electrode layer is formed to be electrically connected to the semiconductor substrate.
Abstract:
A method of fabricating a vertical TDMOS power device using sidewall spacers and a self-align technique and a TDMOS power device of the same. The TDMOS is fabricated using only 3 masks and a source is formed using the self-align technique to embody a highly integrated trench formation. During the process, ion implantation of high concentration into the bottom of the trench makes a thick oxide film grow on the bottom and the corner of the gate, so that electrical characteristic, specifically leakage current and breakdown voltage of the device can be improved. Also, process steps can be much decreased to lower process cost, high integration is possible, and reliability of the device can be improved.
Abstract:
Provided are a semiconductor device and a method of fabricating the same. The method includes: forming a trench in a semiconductor substrate of a first conductive type; forming a trench dopant containing layer including a dopant of a second conductive type on a sidewall and a bottom surface of the trench; forming a doping region by diffusing the dopant in the trench dopant containing layer into the semiconductor substrate; and removing the trench dopant containing layer.
Abstract:
The present invention relates to an input and output port circuit. The input and output port circuit comprises a signal register for storing output signals, an input/output register at which an input/output control signal for determining an input/output direction is stored, a plurality of control registers, a power supply switch circuit for selectively supplying a low voltage or a high voltage depending on a power mode control signal, a signal direction control circuit for determining the direction of the signal depending on a value of the signal register and a value of the input/output register, an output control circuit driven depending on the value of the control register and an output of the signal direction control circuit, and an output driving circuit for outputting the low voltage, the high voltage or the ground value depending on an output of the signal direction control circuit and an output of the output control circuit. The high voltage and the low voltage can be simultaneously driven using only a single output driving circuit and the single output driving circuit is constructed in multiple stages and is selectively driven by the output control register. Therefore, the power consumption can be saved.
Abstract:
A method for fabricating a semiconductor power integrated circuit includes the steps of forming a semiconductor structure having at least one active region, wherein an active region includes a well region for forming a source and a drift region for forming a drain region, forming a trench for isolation of the active regions, wherein the trench has a predetermined depth from a surface of the semiconductor structure, forming a first TEOS-oxide layer inside the trench and above the semiconductor structure, wherein the first TEOS-oxide layer has a predetermined thickness from the surface of the semiconductor device, forming a second TEOS-oxide layer on the first TEOS-oxide layer, wherein a thickness of the second TEOS-oxide layer is smaller than that of the first TEOS-oxide layer, and performing a selective etching to the first and second TEOS-oxide layers, to thereby simultaneously form a field oxide layer pattern, a diode insulating layer pattern and a gate oxide layer pattern, to thereby reduce processing steps and obtain a low on-resistance.
Abstract:
According to a method for manufacturing double RESURF (reduced SURface Field) LDMOS (Lateral Diffused Metal Oxide Semiconductor) transistors, on-resistance of double RESURF LDMOS transistors has been improved by using a new tapered p top layer on the surface of the drift region of the transistor, thereby decreasing the length of the drift region. Another advantage of the current invention is that the breakdown voltage similar with the on-resistance can be improved by using a reproducible tapered TEOS oxide by use of a multi-layer structure and low temperature annealing process. This is due to the reducing of the current path and impurity segregation in the drift region by using the tapered TEOS oxide instead of LOCOS filed oxide.
Abstract:
Provided are a high-quality CMOS image sensor and a photo diode, which can be fabricated in sub-90 nm regime using nanoscale CMOS technology. The photo diode includes: a p-type well; an internal n-type region formed under a surface of the p-type well; and a surface p-type region including a highly doped p-type SiGeC epitaxial layer or a polysilicon layer deposited on a top surface of the p-type well over the internal n-type region. The image sensor includes: a photo diode including an internal n-type region and a surface p-type region; a transfer transistor for transmitting photo-charges generated in the photo diode to a floating diffusion node; and a driving transistor for amplifying a variation in an electric potential of the floating diffusion node due to the photo-charges. The image sensor further includes a floating metal layer for functioning as the floating diffusion node and applying an electric potential from a drain of the transfer transistor to a gate of the driving transistor.
Abstract:
Provided is a wafer exposure apparatus used in a semiconductor device manufacturing process, the exposure apparatus including: a reflective mirror for reflecting light provided from a light source; an optical path changer for changing a path of the light provided from the reflective mirror; first mirrors installed at both sides of the optical path changer to change the path of the light; second mirrors installed at both sides of a material to change the path of the light; and third mirrors installed at both sides of a mask to enter the light reflected by the first mirrors to the mask and to enter the light passed through the mask into the second mirrors, whereby it is possible to continuously expose one surface, both surfaces or a specific surface of a wafer in a state that the wafer is once aligned.