International Business Machines Corporation

James H Comfort

Alfred Grill

Katherine Lynn Saenger

David Edward Kotecki

David Louis Harame

Scott R Stiffler

Raul E Acosta

Alejandro Gabriel Schrott

Tze-Chiang Chen

Vishnubhai Vitthalbhai Patel

Panayotis Constantinou Andricacos

Bernard S Meyerson

Denny D Tang

Pong-Fei Lu

Yuan-Chen Sun

Structures for memory cell applications, including capacitors for DRAM and ferroelectric memory cells from FRAM, whose method of manufacture consists of depositing a ferroelectric or high-epsilon dielectric material to completely fill a cavity whose geometrical width is the sole determinant of the thickness of the electrically active portion of the ferroelectric or high-epsilon dielectric layer in the final device. In the preferred embodiment, the cavity into which the dielectric is deposited is defined by the gap between the plate and stack electrodes which are deposited and patterned in a through-mask plating step prior to the dielectric deposition.

Structure and fabrication method for non-planar memory elements

A capacitor structure with a generally L-shaped non-conductor having a horizontal portion and a vertical portion, the vertical portion defining a first opening formed therein; a generally U-shaped conductor formed within the first opening; and a generally L-shaped conductor formed exterior to the generally L-shaped non-conductor.

Sidewall capacitor with L-shaped dielectric

A capacitor structure is provided, with a first conductor on top of a substrate, a first non-conductor on top of and substantially in register with the first conductor, the first conductor and first non-conductor having a first opening formed therein, a non-conductive sidewall spacer formed in the first opening, the non-conductive sidewall spacer having a second opening formed therein, and a second conductor formed in the second opening.

Isolated sidewall capacitor

Noble metal plating on a preexisting seed layer is used in the fabrication of electrodes for DRAM and FRAM. The plating may be spatially selective or nonselective. In the nonselective case, a blanket film is first plated and then patterned after deposition by spatially selective material removal. In the selective case, the plated deposits are either selectively grown in lithographically defined areas by a through-mask plating technique, or selectively grown as a conformal coating on the exposed regions of a preexisting electrode structure. A diamond-like carbon mask can be used in the plating process. A self-aligned process is disclosed for selectively coating insulators in a through-mask process.

Plating of noble metal electrodes for DRAM and FRAM

The present invention is an isolation structure for use with FET or bipolar devices incorporating a silicon-germanium layer in which the semiconductor devices are isolated by trench structures. A trench is etched through a pad layer, a single crystal silicon layer, a silicon-germanium layer, and finally, into the silicon substrate. The silicon-germanium layer is interposed between the single crystal silicon layer and the silicon substrate and the pad layer covers the single crystal silicon layer. The trench sidewall exposes the silicon-germanium layer. A single crystal silicon layer is formed as a trench liner. This silicon trench liner is then oxidized to passivate the trench isolation. The trench can then be filled with a dielectric without the devices being affected by parasitic leakage caused by the silicon-germanium layer exposed by the trench isolation.

Isolation technique for silicon germanium devices

This invention relates to a bipolar transistor which incorporates, in a raised base regime, an emitter, collector pedestal and intrinsic and extrinsic bases all of which are self-aligned. The invention also relates to a process for fabricating such devices which obtains the self-alignment of the above mentioned elements using a single lithographic and masking step. The structure of the transistor, in addition to having the self-aligned elements, incorporates a composite dielectric isolation layer which not only permits the carrying out of a number of functions during device fabrication but also provides for desired electrical characteristics during device operation. The composite isolation layer consists of an oxide layer adjacent the semiconductor surface; a nitride layer on the oxide layer and an oxide layer on the nitride layer in the final structure of the device. The last mentioned oxide layer starts out early in the fabrication process as a layer of oxidizable material, preferable polycrystalline silicon, which, at later steps in the process, acts as an etch-stop in its unoxidized state and as a memory element and mask in its oxidized state when a self-aligned datum element is removed and the thus exposed underlying dielectric elements must be removed to provide a planar emitter opening. The resulting transistor includes a planar emitter-emitter contact interface which provides for fine control of emitter depth in the underlying intrinsic base region.

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New City, NY, United States of America

James H Comfort