Micron Technology Incorporated

Micron Semiconductor, Inc.

Lsi Logic Corporation

Aftab A Ahmad

Charles H Dennison

Tyler A Lowrey

Kirk D Prall

Pierre C Fazan

David J Keller

Howard E Rhodes

Werner Juengling

Pai-Hung Pan

Klaus Florian Schuegraf

Nanseng Jeng

Randhir P Thakur

Larren Gene Weber

Lyle Jones

Robert S Green

Ruojia R Lee

Mike P Violette

Fernando Gonzales

J Brett Rolfson

Chok J Chia

Michael J Berman

Qwai Hoong Low

Ramaswamy Ranganathan

Brett Rolfson

Brian Benard

A shallow trench isolation is disclosed wherein the trench depth is reduced beyond that achieved in prior art processes. The reduced trench depth helps to eliminate the formation of voids during the trench refill process and provides for greater planarity in the final isolation structure. Effective device isolation is achieved with a reduced trench depth by utilizing refilling dielectric materials having low dielectric constant.

Shallow trench isolation using low dielectric constant insulator

A process is provided for forming an isolating nitride film to isolate gate polysilicon of a gate structure. Specifically, the process comprises providing a channel region defined by a source and drain region of a semiconductor substrate having a gate structure comprising an isolating oxide layer positioned on the channel region and the polysilicon layer positioned on the oxide layer. More specifically, the process comprises the steps of forming the nitrogen implanted regions over the semiconductor substrate by implanting nitrogen atoms into those regions and growing spacers from exposed portions of the polysilicon layer. During the spacer growth, the spacer grows vertically as well as laterally extending under the polysilicon edges. Diffusion of nitrogen atoms to the substrate surface forms silicon nitride under the gate edges, which minimizes current leakages into gate polysilicon.

Fabrication of integrated devices using nitrogen implantation

A barrier layer comprising silicon mixed with an impurity is disclosed for protection of gate dielectrics in integrated transistors. In particular, the barrier layer comprises silicon incorporating nitrogen. The nitrogen can be incorporated into an upper portion of the gate polysilicon during deposition, or a silicon layer doped with nitrogen after silicon deposition. The layer is of particular utility in conjunction with CVD tungsten silicide straps.

Barrier in gate stack for improved gate dielectric integrity

A process for grading the junctions of a lightly doped drain (LDD) N-channel MOSFET by performing a low dosage phosphorous implant after low and high dosage arsenic implants have been performed during the creation of the N-LDD regions and N+ source and drain electrodes. The phosphorous implant is driven to diffuse across both the electrode/LDD junctions and the LDD/channel junctions.

Graded LDD implant process for sub-half-micron MOS devices

A semiconductor structure pad oxide layer is enlarged by local oxidation of silicon to form a field oxide. An etchback causes the thinnest portions of the field oxide to recede such that a portion of the semiconductor substrate is exposed. An etch through the exposed portion of the semiconductor substrate forms a microtrench between the field oxide and the nitride layer with a lateral dimension that is less than that currently achievable by conventional photolithography. The microtrench is then filled by oxide or nitride growth or by deposition of a dielectric material. In another embodiment, formation of the microtrench is carried out as set forth above, but the nitride layer is removed immediately following trench formation. Alternatively, the pad oxide layer is stripped and a new oxide layer is regrown that substantially covers all exposed surfaces of active areas of the semiconductor substrate. The regrown oxide layer will encroach into all exposed surfaces of active areas and will grow also in the microtrench. Alternatively, the pad oxide layer is etched substantially uniformly at regions distant from nitride layer, whereas the etchant concentrates the etch against the nitride layer such that etching is accelerated at this location. Because of accelerated etching at this location, a breach in the pad oxide layer forms before etching of the pad oxide layer has been generally penetrated. The breach has a width of sub-photolithographic limits preparatory to formation of a microtrench thereunder.

Isolation structure having trench structures formed on both side of a locos

An integrated circuit, including a substrate with circuitry formed therein, where the substrate has a peripheral edge. Also included are a top most electrically conductive layer and an underlying electrically conductive layer. Outer bonding pads are disposed in an outer ring, and are formed within the top most layer. Inner bonding pads are disposed in an inner ring, and are formed within the top most layer. Inner connectors electrically connect the inner bonding pads to the circuitry. The inner connectors are formed within the underlying layer, and have a width that is less than the width of the inner bonding pads, thereby defining a gap between the inner connectors. Outer connectors electrically connect the outer bonding pads to the circuitry. The outer connectors are formed within the underlying layer, and have a width that is less than the width of the gap between the inner connectors.

Bonding pad isolation

A process for grading the junctions of a lightly doped drain (LDD) N-channel MOSFET by performing a low dosage phosphorous implant after low and high dosage arsenic implants have been performed during the creation of the N&minus; LDD regions and N&plus; source and drain electrodes. The phosphorous implant is driven to diffuse across both the electrode/LDD junctions and the LDD/channel junctions.

Methods of forming integrated circuitry, methods of forming elevated source/drain regions, and methods of forming field effect transistors are described. In one embodiment, a transistor gate line is formed over a semiconductive substrate. A layer comprising undoped semiconductive material is formed laterally proximate the transistor gate line and joins with semiconductive material of the substrate and comprises elevated source/drain material for a transistor of the line. Subsequently, conductivity-modifying impurity is provided into the elevated source/drain material. In another embodiment, a common step is utilized to provide conductivity enhancing impurity into both elevated source/drain material and material of the gate line. In another embodiment, the undoped semiconductive layer is first patterned and etched to provide elevated source/drain regions prior to provision of the conductivity-modifying impurity. In another embodiment, the semiconductive material is first patterned with conductivity modifying impurity being provided into selected portions of the semiconductive material. Undoped semiconductive portions are subsequently removed selectively relative to doped semiconductive material portions.

Methods of forming integrated circuitry, methods of forming elevated source/drain regions of a field effect transistor, and methods of forming field effect transistors

The invention encompasses a transistor device comprising a region of a semiconductor material, and a transistor gate over a portion of the region. The device comprises a pair of opposing sidewall spacers adjacent sidewalls of the transistor gate and a pair of opposing first conductivity type source/drain regions within the semiconductor material proximate the transistor gate. The entirety of the semiconductor material under one of the sidewall spacers being defined as a first segment, and the entirety of the semiconductor material which is under the other of the sidewall spacers being defined as a second segment. The first and second segments of the semiconductor material are separated from the first and second source/drain regions by first and second gap regions, respectively, of the semiconductor material. The device further comprises a pair of opposing second conductivity type halo regions within the first and second gap regions.

Semiconductor transistor devices and structures with halo regions

Methods of forming integrated circuitry and methods of forming elevated source/drain regions of a field effect transistor

Growing community of inventors

Boise, ID, United States of America

Aftab A Ahmad