Motorola Corporation

Vanguard International Semiconductor Corporation

Other

Howard C Kirsch

Scott S Roth

James D Hayden

Yasunobu Kosa

Ena Ku

Chih-Yuan Lu

Kent J Cooper

Umesh Sharma

Yen-Tai Lin

Bich-Yen Nguyen

James R Pfiester

Michael P Woo

Richard D Sivan

Wayne J Ray

Thomas F McNelly

Ravi Subrahmanyan

Jim Hayden

Frank Kelsey Baker, Jr

Papu D Maniar

Luigi Ternullo, Jr

Janmye Sung

Frank K Baker

Hisao Kawasaki

Yu-Ming Hsu

Lidong Chen

Jason Tzu-Jung Su

A switch level simulation system includes a netlister, a cross-coupled device detector, a cross-coupled device transformer and a switch level simulator. The user provides a circuit a design to the netlister, which generates a netlist of the circuit. The cross-coupled device detector searches the netlist to find all of the cross-coupled devices in the circuit design. The cross-coupled device detector also determines whether the cross-coupled device has a &ldquo;rail&rdquo; node directly connected an external voltage source line. The cross-coupled device transformer transforms each cross-coupled device having a rail node into a transformed cross-coupled device by inserting in the netlist a device at the rail node mirroring the enable device. The mirror device allows the transformed cross-coupled device to provide a high impedance state to emulate the meta-stable state of the cross-coupled device during switch level simulation. The switch level simulator then performs simulations using the netlist with the transformed cross-coupled devices. This technique avoids the need to construct behavioral models of the cross-coupled devices, significantly reducing the engineering resources needed to model cross-coupled devices, while maintaining the accuracy of the switch level simulation.

Switch level simulation with cross-coupled devices

A local bit switch selecting circuit and method for systems having a first number of banks of sense amplifiers with a second number of sense amplifiers in each sense amplifier bank. The bit switch selecting circuit and method use a single N channel field effect transistor in each sense amplifier bank. This provides bit switch selecting capability while significantly reducing the number of devices and chip area required.

Local bit switch decode circuit and method

A current mode data communication system is disclosed. The current mode data communication system has a transmitter to simultaneously transmit two digital data bits. The two digital data bits are combined to form a current mode signal. The current mode signal has a first positive current, a second positive current, a first negative current and a first positive current. The current mode signal will be transmitted on a double bit current mode bus. Further the current mode communication system has a receiver coupled to the double bit current mode bus to receive the current mode signal and convert the current mode signal to a unextracted form of the two digital data bits. The output of the receiver is connected to a data extractor circuit extract the two digital data bits for the unextracted form of the two digital data bits.

Multiple-bit, current mode data bus

A circuit and a method are disclosed for a Schmitt trigger stage which converts transistor-transistor logic (TTL) into metal oxide semiconductor (MOS) logic signal levels using all MOS devices. The circuit reduces the standby current of the n-channel transistor of the input section of the Schmitt trigger stage by adding a MOS diode to the bottom the input section. When higher than normal supply voltages are used, the standby current of the p-channel transistor of the input section can be reduced by adding a MOS diode to the top of the input section. In addition, a small MOS transistor, connected across the output Schmitt trigger inverter, eliminates leakage currents in that inverter.

Schmitt trigger input stage

A method and design for stitching polysilicon wordlines to straps formed of interconnected metal line segments formed in two or more metallization levels. Each strap comprises a continuous conductive metal line passing alternatively from one metal layer to another in a selected sequence. The sequence of segments in each strap alternates in phase with the sequence in next nearest neighbor straps but may be in phase with second nearest neighbor straps. Thereby the pitch of strap segments on each metallization level is at least twice that of the subjacent polysilicon wordlines. The total length of each metal in each strap is the same in all straps. This arrangement allows the use of metals having different resistivities in each strap with all the straps having identical overall resistance. The metals used in the two or more levels may also have different minimum design rules without compromising the identical overall performance of all the straps. In a second embodiment a method and design is described for doubling the length of polysilicon sub-wordlines in a sub-wordline memory array without reducing performance by connecting sub-wordline to sub-wordline decoders by metal straps connected to the sub-wordlines midpoints.

Design for high density memory with relaxed metal pitch

Word line resistance reduction method and design for high density memory

A method, a circuit, and a structure are disclosed by which the semiconductor area is reduced that a local word line decoder for a memory array requires. This reduction in area size has been achieved by eliminating one transistor of a three transistor local wordline decoder and introducing a fifth transistor which is shared by two local wordline decoders. The area occupied by the two eliminated transistors is no longer needed because the fifth transistor can be fitted between two existing transistors without an increase in area.

Local word line decoder for memory with 2 1/2 MOS devices

A method and a circuit are disclosed by which the semiconductor area is reduced that a local word line decoder for a memory array requires. This reduction in area size has been achieved by eliminating one transistor of a three transistor local wordline decoder and by reducing the number of inputs to the decoder from three to two. The reduction in inputs is made possible by the method of applying to one of the inputs, when low, a voltage signal v.sub.b which is at least one threshold lower than the voltage signal to the other input, when low. This voltage v.sub.b can be derived from the p-substrate bias voltage.

Local word line decoder for memory with 2 MOS devices

The present invention provides a method for fabricating a multiple pillar shaped capacitor which has pillars of a smaller dimension than the resolution of the photolithography tool. The invention has two embodiments for forming the pillars and third embodiment for patterning a conductive layer into discrete bottom electrodes. The method begins by forming a conductive layer on a first planarization layer. For the first embodiment, the pillars are formed using a photolithography mask with a pattern of spaced transparent areas. The dimensions of the spaced transparent areas and distances between the spaced transparent areas are smaller then that of the resolution of the lithographic tool. Spaced oxide islands are formed with the mask and are used as an etch mask to form spaced pillars from the conductive layer. The second embodiment for forming the pillars involves using small titanium silicide islands as an etch mask to define the pillars. The third embodiment uses two resist layers and a photo mask shifting (offset) technique to form small spaces between the electrodes. Lastly, a capacitor dielectric layer and a top electrode are formed over the bottom electrodes thereby completing the capacitor with a pillar structure.

Method for forming a capacitor with a multiple pillar structure

A static-random-access memory cell comprising floating node capacitors is disclosed. In one embodiment, the storage nodes acts as the first plates for the floating node capacitors, and a conductive member acts as the second plates for the floating node capacitors. The conductive member also electrically connects the second plates together, but is not electrically connected to other parts of the memory cell. In another embodiment, a conductive member acts as the second plates of a plurality of memory cells. The conductive member also electrically connects the second plates together, but is not electrically connected to other parts of the memory cells. Processes for forming the memory cells is also disclosed.

Semiconductor device having a static-random-access memory cell

A floating gate (51)is formed to have a cavity (52) that increases the capacitive coupling between the floating gate (51) and a control gate for the memory cell. The memory cell may be used in EPROM, EEPROM, and flash EEPROM arrays and may be programmed and erased by hot carrier injection, Fowler-Nordheim tunneling or the like. The process sequence for forming the cavity (52) of the floating gate (51) has good process margin allowing some lithographic misalignment. In one embodiment, a multi-tiered floating gate may be formed. The multi-tier structure allows the capacitive coupling to further increase without occupying more area.

Electrically programmable read-only memory cell

The present invention includes a BiMOS device having an MOS transistor that triggers a bipolar transistor, wherein the base and channel region are formed within a well region that electrically floats. The present invention also includes a BiMOS device having separate regions for the collector and drain regions and for the base and channel regions. The present invention further includes processes for forming the BiMOS devices. The BiMOS device may include a floating well region. The BiMOS device may include both low voltage MOS logic transistors and a high voltage or high power bipolar transistor. A low voltage or low power bipolar transistor may also be used. Separate drain, collector, base, and channel regions allow the bipolar transistor performance to be optimized independently of the MOS transistor, which may have its performance independently optimized, too. A plurality of MOS logic transistors, such as an AND or an OR gate may be used in the BiMOS device.

Growing community of inventors

Austin, TX, United States of America

Howard C Kirsch