摘要:
A static random access memory cell is provided that includes first and second inverters formed on a substrate each having a pull-up and pull-down transistor configured to form a cell node. Each of the pull-down transistors of the first and second inverters resides over first regions below the buried oxide layer and having a first doping level and applied bias providing a first voltage threshold for the pull-down transistors. A pair of passgate transistors is coupled the cell nodes of the first and second inverters, and each is formed over second regions below the buried oxide layer and having a second doping level and applied bias providing a second voltage threshold for the passgate transistors. The first voltage threshold differs from the second voltage threshold providing electrical voltage threshold control between the pull-down transistors and the passgate transistors.
摘要:
A static random access memory cell is provided formed in a silicon layer over a buried oxide layer on a substrate and including first and second inverters each having a pull-up and pull-down transistor configured to form a cell node. Each of the pull-down transistors of the first and second inverters are formed over first regions below the buried oxide layer with the first regions having a first doping level forming first backgates for the pull-down transistors. A pair of passgate transistors respectively couples to the cell nodes of the first and second inverters and each are formed over second regions below the buried oxide layer with the second regions having a second doping level forming second backgates for the passgate transistors. Active bias circuitry applies potentials to the first and second backgates during read, standby and write operations of the static random access memory cell.
摘要:
A design process includes inputting a design file representing a circuit design embodied in a non-transitory computer-readable medium, and using a computer to translate the circuit design into a netlist. The netlist comprises a representation of a plurality of wires, transistors, and logic gates, and is stored in the non-transitory computer-readable medium. When executed by the computer, the netlist produces the circuit design. The circuit design comprises a static random access memory (“SRAM”) including a plurality of SRAM cells arranged in an array, including a plurality of rows and a plurality of columns, and a plurality of column voltage control circuits corresponding to respective ones of the plurality of columns of the array. Each of the plurality of voltage control circuits is coupled to an output of a power supply and is operable to temporarily reduce a voltage upon arrival of a bit select signal provided to power supply inputs of a plurality of SRAM cells belonging to a selected column of the plurality of columns. The selected column is selected during a write operation in which a bit is written to one of the plurality of SRAM cells belonging to the selected column. Each column voltage control circuit includes an NFET and a pair of PFETs. Each NFET and pair of PFETs has a conduction path directly connected between the output of the power supply and the power supply inputs of the plurality of SRAM cells.
摘要:
An array of deep trenches is formed in a doped portion of the semiconductor substrate, which forms a lower electrode. A dielectric layer is formed on the sidewalls of the array of deep trenches. The array of deep trenches is filled with a doped semiconductor material to form an upper electrode comprising a top plate portion and a plurality of extension portions into the array of trenches. In a depletion mode, the bias condition across the dielectric layer depletes majority carriers within the top electrode, thus providing a low capacitance. In an accumulation mode, the bias condition attracts majority carriers toward the dielectric layer, providing a high capacitance. Thus, the trench metal-oxide-semiconductor (MOS) varactor provides a variable capacitance depending on the polarity of the bias.
摘要:
A design structure including a static random access memory (“SRAM”) is provided which includes a plurality of SRAM cells arranged in an array. The array includes a plurality of rows and a plurality of columns. The SRAM includes voltage control circuits corresponding to respective ones of the plurality of columns of the array, each coupled to an output of a power supply. Each voltage control circuit temporarily reduces a voltage provided to power supply inputs of a plurality of SRAM cells that belong to a selected column of columns of the SRAM. The power supply voltage to the selected column is reduced during a write operation in which a bit is written to one of the SRAM cells belonging to the selected column.
摘要:
Methods for fabricating a heterojunction bipolar transistor having a raised extrinsic base is provided in which the base resistance is reduced by forming a silicide atop the raised extrinsic base that extends to the emitter region in a self-aligned manner. The silicide formation is incorporated into a BiCMOS process flow after the raised extrinsic base has been formed. The present invention also provides a heterojunction bipolar transistor having a raised extrinsic base and a silicide located atop the raised extrinsic base. The silicide atop the raised extrinsic base extends to the emitter in a self-aligned manner. The emitter is separated from the silicide by a spacer.
摘要:
The present invention provides a device design and method for forming Field Effect Transistors (FETs) that have improved performance without negative impacts to device density. The present invention forms high-gain p-channel transistors by forming them on silicon islands where hole mobility has been increased. The hole mobility is increased by applying physical straining to the silicon islands. By straining the silicon islands, the hole mobility is increased resulting in increased device gain. This is accomplished without requiring an increase in the size of the devices, or the size of the contacts to the devices.
摘要:
A method of forming conductive contacts to drain and source regions of a semiconductor device such as a field effect transistor (FET). A gate structure is formed over a portion of a semiconductor substrate, wherein the gate structure includes: a gate dielectric on a surface of the semiconductor substrate, a conductive gate aligned on the gate dielectric, a silicide layer aligned on the conductive gate, and a silicon nitride cap aligned on the silicide layer. Insulative spacers are formed on sidewalls of the gate structure, and the insulative spacers contact the semiconductor substrate. A drain region and a source region are formed within the semiconductor substrate, wherein a channel region is disposed between the drain region and the source region, and wherein the gate structure is over the channel region. After an insulative region containing a photosensitive material, such as boro-phoso-silicate glass, is formed over the gate structure and the semiconductor substrate, a cavity over the drain region and a cavity over the source region are formed photolithographically. The cavities are filled with conductive material such as tungsten, forming a conductive contact to the drain region and a conductive contact to the source region. The top surfaces of the conductive contacts and the top surface of the gate structure are coplanar.
摘要:
A method of forming conductive contacts to drain and source regions of a semiconductor device such as a field effect transistor (FET). A gate structure is formed over a portion of a semiconductor substrate, wherein the gate structure includes: a gate dielectric on a surface of the semiconductor substrate, a conductive gate aligned on the gate dielectric, a silicide layer aligned on the conductive gate, and a silicon nitride cap aligned on the silicide layer. Insulative spacers are formed on sidewalls of the gate structure, and the insulative spacers contact the semiconductor substrate. A drain region and a source region are formed within the semiconductor substrate, wherein a channel region is disposed between the drain region and the source region, and wherein the gate structure is over the channel region. After an insulative region containing a photosensitive material, such as boro-phoso-silicate glass, is formed over the gate structure and the semiconductor substrate, a cavity over the drain region and a cavity over the source region are formed photolithographically. The cavities are filled with conductive material such as tungsten, forming a conductive contact to the drain region and a conductive contact to the source region. The top surfaces of the conductive contacts and the top surface of the gate structure are coplanar.
摘要:
A semiconductor integrated circuit memory cell, including at least three transistors and a capacitor to form a DRAM. The memory cell is fabricated on a semiconductor substrate including impurity regions, and using two semiconductor films, with dielectric films between the semiconductor films. The capacitor contains two electrodes. A substrate impurity region forms one of the electrodes; the other electrode is a semiconductor film which connects the gate of one device to an impurity region of another. The method for manufacturing the above-described integrated circuit, which may be used for the manufacture of similar circuits, is also disclosed.