Lsi Logic Corporation

Wen-Chin Stanley Yeh

Arvind Kamath

Venkatesh P Gopinath

Jiunn-Yann Tsai

Shiuh-Luen Wang

Zhihai Wang

Weidan Li

Rajat Rakkhit

Linggian Qian

Chiang-Sheng Yao

David Pachura

A method of producing an antifuse includes introducing nitrogen by ion implantation means into the substrate. An oxide dielectric layer is then formed on the nitrided substrate in a wet oxidation ambient. The conditions of the ion implantation and the oxidation are controlled to generate a dielectric with uniform thickness and a low breakdown voltage when subjected to a high electric field.

Method of forming an antifuse on a semiconductor substrate using wet oxidation of a nitrided substrate

Growth of multiple gate oxides. By implanting different sites of a wafer with different doses of an oxide growth retardant, the entire wafer can grow oxides of different thicknesses even after being exposed to the same oxidation environment. The process is modular insofar as the implantation of one site has no effect on rate of growth of other sites.

Modular growth of multiple gate oxides

A local interconnect for an integrated circuit structure is described capable of bridging over a conductive element to electrically connect together, at the local interconnect level, non-adjacent conductive portions of the integrated circuit structure. After formation of active devices and a conductive element of an integrated circuit structure in a semiconductor substrate, a silicon oxide mask is formed over the structure, with the conductive element covered by the silicon oxide mask. Metal silicide is then formed in exposed silicon regions beneath openings in the mask. The portion of the silicon oxide mask covering the conductive element is then retained as insulation. A silicon nitride etch stop layer and a planarizable dielectric layer are then formed over the structure. An opening is then formed through such silicon nitride and dielectric layers over the conductive element and exposed metal silicide regions adjacent the conductive element. Conductive metal is then deposited over the entire structure to fill the opening. The conductive metal thereby forms a local interconnect which bridges over the conductive element to electrically connect the respective exposed metal silicide regions adjacent the conductive element, with the silicon oxide retained over the conductive element providing insulation to electrically separate the local interconnect from the conductive element. A formula is also provided for calculating the thickness range of the silicon oxide mask layer when a silicon nitride etch stop layer is utilized.

Tungsten local interconnect for silicon integrated circuit structures, and method of making same

An integrated circuit structure is provided with an inductor formed therein which comprises a metal coil on an insulated surface over a semiconductor substrate, and a high magnetic susceptibility cobalt/nickel metal core located adjacent said metal coil, but spaced therefrom by one or more insulation layers. In one embodiment, the high magnetic susceptibility cobalt/nickel metal core is placed between lower and upper portions of the metal coil which are interconnected together by filled vias. In another embodiment, the metal coil is formed in a serpentine shape in one plane on an insulated surface over the semiconductor substrate, and the high magnetic susceptibility cobalt/nickel metal core is formed over the serpentine coil, but spaced from the serpentine coil by another insulation layer.

Inductor with cobalt/nickel core for integrated circuit structure with

A metal silicide blocking process for preventing formation of metal silicide on a first device and allowing formation of metal silicide on elements of a second device of an integrated circuit substrate is described. The process includes forming a gate electrode above the integrated circuit substrate, forming a first dielectric layer over the gate electrode and the substrate surface, forming a second dielectric layer above the first dielectric layer, etching anisotropically the second dielectric layer to form a second spacer portion adjacent to the first dielectric layer; masking the substrate surface of the first device to protect the first dielectric layer above the first device from being removed such that the substrate surface at the second device where the metal silicide is to be formed is exposed, etching the first dielectric layer to form a first spacer portion disposed between the gate electrode of the second device and the second spacer portion, the first spacer portion extends underneath the second spacer portion such that the first spacer portion is disposed between the second spacer portion and a portion of the substrate disposed beneath the second spacer portion, exposing the substrate surface of the first device, depositing a metal layer on the substrate surface and fusing metal ions from the metal layer with silicon ions from a plurality of device elements from the portion of the substrate surface where the metal silicide is to be formed to form metal silicide contact areas above the plurality of device elements.

Effective silicide blocking

A method for hardening of gate oxide without forming low dopant concentration regions at the gate oxide-polysilicon interface is described. Polysilicon is deposited onto gate oxide followed by nitrogen implantation and annealing. At this point nitrogen concentration peaks exist at the gate oxide interfaces with the single crystal substrate and the polysilicon gate electrode. This effectively hardens the gate oxide. A third polysilicon gate electrode exists in the bulk of the polysilicon gate electrode. In the described process the region of the polysilicon layer that contains the nitrogen concentration peak is removed. An electronically active dopant may then be implanted. Alternatively, a fresh polysilicon layer may then be deposited followed by implantation of an electronically active dopant. Thus, the method of the invention avoids retardation of electronically active dopant diffusion.

Nitrogen implanted polysilicon gate for MOSFET gate oxide hardening

An improved process is provided for amorphizing portions of a silicon substrate and a polysilicon gate electrode surface to be converted to metal silicide by subsequent reaction of the amorphized silicon with a metal layer applied over the silicon substrate and polysilicon gate electrode after the amorphizing step. The improvement comprises implanting the exposed surface of the silicon substrate and the surface of the polysilicon gate electrode with a beam of amorphizing ions at an angle of at least 15.degree. to a line perpendicular to the plane of the surface of the silicon substrate to thereby inhibit channeling of the implanted ions through the gate electrode to the underlying gate oxide and channel of the MOS structure. The implant angle of the beam of amorphizing ions is preferably at least 30.degree., but should not exceed 60.degree., with respect to a line perpendicular to the plane of the surface of the silicon substrate.

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Fremont, CA, United States of America

Wen-Chin Stanley Yeh