Fairchild Semiconductor Corporation

Daniel J Hahn

Steven M Leibiger

Ronald B Hulfachor

Michael Harley-Stead

James Hall

Jifa Hao

Sunglyong Kim

Christopher Nassar

Laurence M Szendrei

In a general aspect, a high-voltage metal-oxide-semiconductor (HVMOS) device can include comprising a first gate dielectric layer disposed on a channel region of the HVMOS device and a second gate dielectric layer disposed on at least a portion of a drift region of the HVMOS device. The drift region can be disposed laterally adjacent to the channel region. The second gate dielectric layer can have a thickness that is greater than a thickness of the first gate dielectric layer.

Reduction of degradation due to hot carrier injection

In one general aspect, a semiconductor processing method can include forming an N-type silicon region disposed within a P-type silicon substrate. The method can also include forming a field oxide (FOX) layer in the P-type silicon substrate where the FOX layer includes an opening exposing at least a portion of the N-type silicon region. The method can further include forming a reduced surface field (RESURF) oxide (ROX) layer having a first portion disposed on the exposed N-type silicon region and a second portion disposed on the FOX layer where the ROX layer includes a first dielectric layer in contact with the exposed N-type silicon region and a second dielectric layer disposed on the first dielectric layer. The method can further include forming a doped polysilicon layer having a first portion disposed on the first portion of the ROX layer and a second portion disposed on the second portion of the ROX layer.

Production of high-performance passive devices using existing operations of a semiconductor process

A CMOS device with polysilicon protection tiles is shown in FIG.. LOCOS regionsandseparate adjacent active regionsfromandfrom, respectively. On the upper surface of the LOCOS regionsare polysilicon tiles, respectively. At the corner of the gate polysiliconand the polysilicon tilesandare oxide spacers-. The polysilicon tileshave silicide layers. Other silicide layers-are on the tops of the source, drain and polysilicon gate. An insulation layercovers the substrate and metal contactsextend from the surface of the layerto the silicide layers on the source, gate and drain, respectively. The polysilicon tiles are made from the same layer of polysilicon as the gate and they are formed simultaneously with the gates. The intention of the polysilicon tiles is to reduce erosion of the field oxide between closely spaced active regions. In addition, the poly tiles themselves increase the thickness of the isolation between active silicon regions when it must serve as a self-aligned blocking layer for an ion implantation step.

Method for enhancing field oxide

An emitter stack for a quasi-self-aligned bipolar (NPN or PNP) transistor is formed where two layers over the emitter of a silicon substrate are windowed in a manner to under cut the top layer thereby exposing the substrate material. The emitter polysilicon structure is then formed over the window and conformally extends into the undercut region thereby widening the emitter region and so reducing the distance between the edge of the emitter and the extrinsic base (the base link distance) and therefore reducing the total base resistance of the transistor.

Quasi self-aligned single polysilicon bipolar active device with intentional emitter window undercut

A structure of and a method for making an isolated NMOS transistor using standard BiCMOS processing steps and techniques. No additional masks and processing steps are needed for the isolated NMOS device relative to the standard process flow. A P-type substrate with an overlaying buried N-type layer overlaid with a buried p-type layer below a P-well is shown. An N-type region surrounds and isolates the P-well from other devices on the same wafer. N+ regions are formed in the p-well for the source and drain connections and poly or other such electrical conductors are formed on the gate, drain and source structures to make the NMOS device operational. Parasitic bipolar transistors are managed by the circuit design, current paths and biasing to ensure the parasitic bipolar transistors do not turn on.

Method and structure for BiCMOS isolated NMOS transistor

An ESD protection device including a transistor structure with resistive regions located within active areas thereof. The transistor structure is formed of one or more MOS transistors, preferably N-type MOS transistors. The drain regions of the transistors are modified to reduce the conductivity of those resistive regions by preventing high carrier concentration implants in one or more sections of the drain regions. This is achieved by modifying an N LDD mask and the steps related thereto, as well as a silicide exclusion mask and the steps related thereto. The modifications result in the omission of N LDD dopant from the area immediately adjacent to the underlying channel. In addition, portions of a spacer oxide remain over the drain region to be formed. Subsequent implant and siliciding steps are effectively blocked by the spacer oxide that remains, leaving a low-density drain (LDD) charge carrier concentration in those regions, except where omitted. The resistivity of those resistive LDD regions is greater than the resistivity of the adjacent portions of the drain region. The result is more uniform turn-on of ESD transistor fingers in a protection device set without the need to add valuable layout space and without increased processing steps.

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Cumberland, ME, United States of America

Daniel J Hahn