International Business Machines Corporation

Other

Siemens Aktiengesellschaft

Manfred Hauf

Max Gerald Levy

Victor R Nastasi

Son Van Nguyen

William J Cote

Donna Rizzone Cote

Markus M Kirchhoff

A process for fabricating a device including the step of forming a structure for facilitating the passivation of surface states is disclosed. The structure comprises an oxynitride layer formed as part of the device structure. The oxynitride facilitates the passivation of surface states when heated.

Semiconductor device structure with hydrogen-rich layer for facilitating passivation of surface states

A Field Effect Transistor (FET) and a method of forming FETs on a silicon wafer. First, trenches are formed in a surface of the silicon wafer. An ONO layer is formed on the surface, lining the trenches. Potassium is diffused along the ONO layer. Part of the ONO layer is removed to expose the wafer surface with the ONO layer remaining in the trenches. A gate oxide is formed on the exposed wafer surface. Finally, FET gates are formed on the gate oxide. Preferably, potassium is introduced during Chem-Mech polish when the trenches are filled with polysilicon. A slurry containing KOH is used to polish the polysilicon and the potassium diffuses from the slurry along the ONO layer. After Chem-Mech polish, the poly in the trenches is recessed by Reactive Ion Etching (RIE) it below the wafer surface. Optionally, after RIE, the wafer may be dipped in a KOH solution. Next, an oxide collar is formed along the ONO layer in the trenches above the recessed polysilicon. The recesses are filled by a second layer of polysilicon that is Chem-Mech polished with the same slurry to remove polysilicon from the wafer surface. The polished polysilicon may be Reactive Ion etched until it is essentially coplanar with the wafer surface. The resulting FET has thicker gate oxide along its sides than in the center of its channel.

Method of manufacturing an insulated gate field effect transistor

An FET isolated on either side by a trench. The FET has a dielectric layer in the isolating trench along at least one side. The dielectric layer which may be an ONO layer has an oxidation catalyst diffused into it. The oxidation catalyst may be potassium. A gate oxide along the side of the FET in close proximity to the ONO layer is thicker than gate oxide between both sides.

Insulated gate field effect transistor

An integrated circuit with FETs having an essentially uniform gate oxide thickness and FETs having gate oxide thickness enhanced along the sides. FETs with enhanced gate oxide have an ONO layer diffused with potassium in close proximity to the enhanced (thicker) oxide, and, as a result, have a slightly higher V.sub.t and much more attenuated soft turn on.

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Wappingers Falls, NY, United States of America

Manfred Hauf