International Business Machines Corporation

James Patrick Norum

Kangguo Cheng

Byeong Yeol Kim

Stefan Schmitz

Munir D Naeem

Christopher N Collins

Harris C Jones

Subramanian Srikanteswara Iyer

Johnathan E Faltermeier

Kwong Hon Wong

Paul Christian Parries

Hongwen Yan

Kenneth John Giewont

Chienfan Yu

Peter Stevens Locke

Jin J Wu

William A Cavaliere

Delores A Bennett

Lawrence Bauer, Jr

Bosang Kim

Jeffrey Lloyd

Kent Way

An integrated circuit including a trench capacitor has a semiconductor region in which a material composition varies in a quantity of at least one component therein such that the quantity alternates with depth a plurality of times between at least two different values. For example, a concentration of a dopant or a weight percentage of a second semiconductor material, such as germanium, in a semiconductor alloy can alternate between with depth a plurality of times between higher and lower values. The trench capacitor has an undulating capacitor dielectric layer, wherein the undulations of the capacitor dielectric layer are at least partly determined by the undulating interior surface of the trench. Such trench capacitor can provide enhanced capacitance, and can be incorporated in a memory cell such as a dynamic random access memory ('DRAM') cell, for example.

Enhanced capacitance trench capacitor

A method of fabricating a trench capacitor is provided in which a material composition of a semiconductor region of a substrate varies in a quantity of at least one component therein such that the quantity alternates with depth a plurality of times between at least two different values. For example, a concentration of a dopant or a weight percentage of a second semiconductor material in a semiconductor alloy can alternate between with depth a plurality of times between higher and lower values. In such method, the semiconductor region can be etched in a manner dependent upon the material composition to form a trench having an interior surface which undulates in a direction of depth from the major surface of the semiconductor region. Such method can further include forming a trench capacitor having an undulating capacitor dielectric layer, wherein the undulations of the capacitor dielectric layer are at least partly determined by the undulating interior surface of the trench. Such trench capacitor can provide enhanced capacitance, and can be incorporated in a memory cell such as a dynamic random access memory ('DRAM') cell, for example.

Method of forming enhanced capacitance trench capacitor

A deep trench structure process for forming a deep trench in a silicon on insulator (SOI) substrate. The SOI substrate has a bulk silicon layer, a buried oxide (BOX) layer and an SOI layer. In the process, the trench fill is recessed only to a level within the SOI layer so as to avoid lateral etching of the BOX layer. The buried strap is then formed followed by the STI oxide.

eDRAM memory cell structure and method of fabricating

A method is provided for forming a polysilicon layer on a substrate and aligning an exposure system with an alignment feature of the substrate through the polysilicon layer. In such method, a polysilicon layer is deposited over the substrate having the alignment feature such that the polysilicon layer reaches a first temperature. The polysilicon layer is then annealed with the substrate to raise the polysilicon layer to a second temperature higher than the first temperature. A photoimageable layer is then deposited over the polysilicon layer, after which an alignment signal including light from the alignment feature is received through the annealed polysilicon layer. Using the alignment signal passing through the annealed polysilicon layer from the alignment feature, an exposure system is aligned with the substrate with improved results.

Polysilicon hard mask for enhanced alignment signal

The integrity of a liner in an interconnect structure or other layer in an integrate circuit is tested in a short time by exposing the liner to a reactive gas that attacks the underlying silicon or other material behind the liner. A weak spot in the liner permits the gas to react with the silicon, which produces a visible area that can be readily identified. The test can be performed in a few hours, in contrast to a period of several months required to complete the process, package the circuit and conduct a burn-in test.

Early detection of contact liner integrity by chemical reaction

A trench capacitor having an increased surface area. In one embodiment, the trench capacitor is a dual trench capacitor having a first trench and a second trench wherein inner walls of the trenches electrically connect. The invention also includes a single trench capacitor wherein the trench is curved around an axis substantially perpendicular to a substrate surface.

Process of manufacturing a DRAM cell capacitor having increased trench capacitance

A process of etching an oxide layer placed over a nitride layer of a substrate with high selectivity. The process comprises plasma etching the oxide layer of the substrate with a carbon and fluorine-containing gas and with a nitrogen-containing gas. A Si,N,species is formed which is deposited on the nitride layer substantially in equilibrium with etching of the nitride layer.

Selective dry etch of a dielectric film

DRAM cell capacitor having increased trench capacitance

A cryogenic aerosol separator/classifier for separating and selectively removing particles from a stream of aerosol. The aerosol stream is produced by a cryogenic aerosol generator comprising a reservoir containing a cryogenic gas-liquid mixture at a first pressure, a delivery line coupled to the reservoir, and a nozzle. The nozzle has at least one exit opening which allows the cryogenic gas-liquid mixture to expand from the first pressure to a lower pressure and, thus, to produce cryogenic aerosol. A separator is coupled to the nozzle, such that the light particles having high mobility are removed from the stream, thereby producing a stream of cryogenic flow with particles having a controlled size to clean a contaminated surface. The apparatus is enhanced by utilizing a magnetic field and/or specially designed flow fields to fully take advantage of the enhanced mobilities of light particles.

Cryogenic aerosol separator

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Holmes, NY, United States of America

James Patrick Norum