摘要:
A method for fabricating a MOS transistor having an offset resistance in a channel region controlled by a gate voltage and structure thereof is disclosed. A gate electrode is divided into three adjacent regions of respectively a second conductivity type, first conductivity type and second conductivity type connected laterally to one another on a channel region. A gate control voltage is applied to a central region of the first conductivity type, and a predetermined voltage between maximum and minimum values of the gate control voltage is applied to left and right adjacent regions of the second conductivity type. If a gate turn-on voltage is applied to the central region the gate turn-on voltage is forward biased to the adjacent left and right regions and is therefore also applied to the forwardly biased left and right regions. The effective length of the gate electrode then becomes the total length of the central region and the left and right adjacent regions. If a gate turn-off voltage is applied to the central region the central region becomes reverse biased with the left and right adjacent regions and thus the effective length of the gate electrode becomes the length of only the central region of the first conductivity type. This reduces the length of the channel region, and thus forms an offset resistance structure which reduces leakage current in the off state of the MOS transistor.
摘要:
Methods of forming thin-film transistors include the steps of forming an amorphous silicon (a-Si) layer of predetermined conductivity type on a face of an electrically insulating substrate and then forming a first insulating layer on the amorphous silicon layer. The first insulating layer and amorphous silicon layer are then patterned to define spaced amorphous source and drain regions having exposed sidewalls. An amorphous silicon channel region is then deposited in the space between the source and drain regions and in contact with the sidewalls thereof. An annealing step is then performed to convert the amorphous source, drain and channel regions to polycrystalline silicon, prior to the step of forming an insulated gate electrode on the channel region.
摘要:
To accomplish the objects of the present invention, among others, the present invention provides a thin-film transistor that has a channel region operatively having an offset region only during turn-off. Source and drain regions self-aligned with different ends of the channel region. A gate region is formed on a gate insulating layer disposed over the channel region and has a main gate accepting a gate voltage, a subgate which comes into ohmic contact with the source region, and a junction gate for forming a rectifying junction between the main gate and subgate.
摘要:
A method for fabricating a MOS transistor having an offset resistance in a channel region controlled by a gate voltage and structure thereof is disclosed. A gate electrode is divided into three adjacent regions of respectively a second conductivity type, first conductivity type and second conductivity type connected laterally to one another on a channel region. A gate control voltage is applied to a central region of the first conductivity type, and a predetermined voltage between maximum and minimum values of the gate control voltage is applied to left and right adjacent regions of the second conductivity type. If a gate turn-on voltage is applied to the central region the gate turn-on voltage is forward biased to the adjacent left and right regions and is therefore also applied to the forwardly biased left and right regions. The effective length of the gate electrode then becomes the total length of the central region and the left and right adjacent regions. If a gate turn-off voltage is applied to the central region the central region becomes reverse biased with the and left and right adjacent regions and thus the effective length of the gate electrode becomes the length of only the central region of the first conductivity type. This reduces the length of the channel region, and thus forms an offset resistance structure which reduces leakage current in the off state of the MOS transistor.
摘要:
A process for manufacturing an offset gate structure thin film transistor which includes the steps of forming a first semiconductor layer, e.g., an active layer made of amorphous silicon or polysilicon, on a major surface of a substrate, e.g., a glass substrate of an LCD, forming a buffer layer on the first semiconductor layer, etching away a first region of the buffer layer and etching a corresponding region of the first semiconductor layer to a predetermined depth, to thereby form a recess and an underlying thin channel region in the first semiconductor layer, the thin channel region having a thickness less than that of the remainder of the first semiconductor layer, forming a second semiconductor layer on the buffer layer and exposed portions of the first semiconductor layer defining the recess, forming a gate insulating layer on the second semiconductor layer, forming a conductive layer on the gate insulating layer, etching the second semiconductor layer, the gate insulating layer, and the conductive layer so as to form a gate electrode structure overlying the thin channel region of the first semiconductor layer and offset resistance regions of the first semiconductor layer disposed on opposite sides of the thin channel region, and, ion-implanting impurities into the first semiconductor layer through exposed portions of the buffer layer disposed on opposite sides of the gate electrode structure, to thereby form source and drain regions on opposite sides of the offset resistance regions of the first semiconductor layer.
摘要:
A field effect transistor includes laterally spaced apart source and drain regions in a substrate, laterally spaced apart undoped regions in the substrate between the laterally spaced apart source and drain regions, a doped channel region in the substrate between the laterally spaced apart undoped regions, and a gate insulating layer on the substrate. A main gate is on the gate insulating layer opposite the channel, and first and second sub gates are on the gate insulating layer, a respective one of which is opposite a respective one of the spaced apart undoped regions. The first and second sub gates are laterally spaced apart from and electrically insulated from the main gate. The transistor may be formed by patterning a photoresist layer and a gate layer to form a main gate and first and second sub gates, reflowing the photoresist into the lateral space between the main gate and the first and second sub gates, etching the gate insulating layer using the reflowed photoresist as a mask, and implanting ions into the substrate to form source and drain regions using the etched gate insulating layer as a mask.
摘要:
A data transmission circuit capable of a high-speed data input/output operation and a large-scaled integration for use in a semiconductor memory device, is disclosed. The data transmission circuit has at least one memory cell 51, a word line 52, a pair of bit lines 65, 66, a sense amplifier 55, and a pair of isolation transistors 53, 54. Further, the circuit includes a pair of common input/output lines 67, 68 for transmitting input or output data with a complementary logic operation, a discharging transistor 56 receiving a control signal at its gate and having a channel connected with a ground voltage node, for transferring an electric potential applied to one end of the channel into the ground voltage level, and a pair of transmission transistors 59, 60 receiving the control signal at their respective gates and having each channel connected with the common input/output lines. Two pairs of input transistors 61, 62 and 63, 64 are connected with the bit lines, their channels each being connected between the bit lines 65, 66 and the transmission transistors 59, 60, their gates each connected with the input/output lines. A pair of output transistors 57, 58 each have a gate electrode connected to the bit lines, and having a channel connected between the channel of the discharging transistor 56 and the channel of the transmission transistors 59, 60. To control electrodes of the discharging transistor 56 and the first and second transmission transistor 59, 60 is applied a column selection line (CSL) signal.
摘要:
A field effect transistor includes laterally spaced apart source and drain regions in a substrate, laterally spaced apart undoped regions in the substrate between the laterally spaced apart source and drain regions, a doped channel region in the substrate between the laterally spaced apart undoped regions, and a gate insulating layer on the substrate. A main gate is on the gate insulating layer opposite the channel, and first and second sub gates are on the gate insulating layer, a respective one of which is opposite a respective one of the spaced apart undoped regions. The first and second sub gates are laterally spaced apart from and electrically insulated from the main gate. The transistor may be formed by patterning a photoresist layer and a gate layer to form a main gate and first and second sub gates, reflowing the photoresist into the lateral space between the main gate and the first and second sub gates, etching the gate insulating layer using the reflowed photoresist as a mask, and implanting ions into the substrate to form source and drain regions using the etched gate insulating layer as a mask.
摘要:
A field effect transistor includes laterally spaced apart source and drain regions in a substrate, laterally spaced apart undoped regions in the substrate between the laterally spaced apart source and drain regions, a doped channel region in the substrate between the laterally spaced apart undoped regions, and a gate insulating layer on the substrate. A main gate is on the gate insulating layer opposite the channel, and first and second sub gates are on the gate insulating layer, a respective one of which is opposite a respective one of the spaced apart undoped regions. The first and second sub gates are laterally spaced apart from and electrically insulated from the main gate. The transistor may be formed by patterning a photoresist layer and a gate layer to form a main gate and first and second sub gates, reflowing the photoresist into the lateral space between the main gate and the first and second sub gates, etching the gate insulating layer using the reflowed photoresist as a mask, and implanting ions into the substrate to form source and drain regions using the etched gate insulating layer as a mask.