Disclosed is a process for making VLSI integrated circuits and a local interconnect system, wherein first poly, second poly and moat are all interconnected in any desired pattern by a TiN local interconnect. No masks are required beyond those which would be required for the two poly levels and local interconnect capability anyway.

Process for making integrated circuits having titanium nitride triple interconnect

An SRAM using TiN local interconnects. This permits the moat parasitic capacitance to be reduced, and also avoids use of metal jumpers, resulting in increased density.

SRAM with local interconnect

A new integrated circuit structure, wherein a TiN thin film layer 129 and another patterned thin film layer 124 preferably comprising polysilicon are separated (in some locations) by a thin dielectric 132 to define capacitors. At various other locations, the TiN layers 129 also makes contact to the polysilicon layer 124 (which will be silicide-clad at these locations), makes contact to n+ substrate regions 134 and p+ substrate regions 136, and also to provide a contact pad for a third patterned thin film conductor layer which overlies the other two. One important class of embodiments provides a floating-memory cell. wherein the floating gate 120 is made of polysilicon, but the control gate 142 consists predominantly of titanium nitride. A novel process for forming the titanium nitride control gate 142 and simultaneously forming titanium nitride local interconnect lines 149 is also disclosed.

Integrated circuit device and process with tin capacitors

A local interconnect system for VLSI integrated circuits. During self-aligned silicidation of exposed moat and gate regions in a nitrogen atmosphere, a conductive titanium nitride layer is formed overall. Normally this conductive layer is stripped to avoid shorting out devices. However, the present invention patterns this conductive layer, thereby providing a local interconnect with the sheet resistance of the order of one ohm per square. Moreover, this local interconnect level permits contacts to be misaligned with the moat boundary, since the titanium nitride local interconnect layer can be overlapped from the moat up on to the field oxide to provide a bottom contact and diffusion barrier for a contact hole which is subsequently etched through the interlevel oxide. This local interconnect level fulfills all of the functions which a buried contact layer could fulfill, and fulfills other functions as well.

VLSI local interconnect structure

VLSI interconnect method and structure

A complementary MOS inverter includes transistors each of which has a dual gate structure with the threshold voltage of the channel nearest the drain of each transistor arranged to be lower than that of the channel nearest the source of each transistor. This arrangement provides the cascode characteristics of dual gate structure, i.e., high breakdown voltage, high voltage gain, low drain output conductance, and relatively fast frequency response, but allows all four gate electrodes of the transistors to be connected in common, thus enabling relatively simple layout.

Jun James Murgen Cartwright

Papers

Complementary MOS inverter structure

Komplementaer-mos-inverter