Lucent Technologies Inc.

At+t Corp.

Agere Systems Inc.

Tseng-Chung Lee

Helen Louise Maynard

Edward Alois Rietman

Dale E Ibbotson

Avinoam Kornblit

Nadine Blayo

Heon Lee

Glenn B Alers

Gardy Cadet

Daniel Joseph Vitkavage

Edward Alois Reitman

Nacer Layadi

Arnaud Grevoz

Dale Edward Ibbotson

A capacitor structure is formed in a window in a dielectric layer of an integrated circuit. The lower electrode (or plate) is disposed on a portion side surface of the cavity but not on the top surface of the dielectric. A layer of dielectric material is disposed on the lower electrode and upon the top surface of the integrated circuit dielectric. Finally, an upper electrode (or plate) is disposed on the layer of dielectric material. Because the lower electrode is removed from a portion of the cavity sidewall and top surface of the dielectric shorting problems which could result during planarization are avoided. A technique for fabricating an integrated circuit (IC) for use in multi-level structures is also disclosed. The technique is readily incorporated into standard multi-level processing techniques. After a window is opened in the particular dielectric layer of the IC, a conductive layer is deposited in the window and forms the lower plate of a capacitor. The lower plate is then etched so that it is removed from a portion of the sidewalls and from the top surface of the dielectric layer. After the lower electrode is etched, a dielectric material is disposed in the cavity and on the top surface of the dielectric layer. A second layer of conductor is disposed on top of the dielectric material layer, thus completing the capacitor structure.

Damascene capacitors for integrated circuits

The specification describes an interferometric in-situ end point detection technique for plasma etching in which the end point is predicted before any overetching occurs. It is based on the recognition that the wavelength of the monitoring beam can be selected so that only a single interferometric fringe appears before clearing. Knowing there is only one fringe, detection is simplified and the etching process can be terminated while a finite but small thickness of the layer remains. This allows etching partial thicknesses of layers. It also allows a two step etch process wherein the etch chemistry can be changed to a highly selective etch to complete clearing of the layer.

Etch endpoint detection

A data visualization method and apparatus permit the representation of multi-dimensional input data sequences as output sequences of closed form visual representations known as blobs. By noting changes in the shape of blobs as processing of the input sequence progresses, changes in characteristics of entities represented by the input sequence can be readily ascertained by observation. In an illustrative embodiment, a plasma etching process used in semiconductor fabrication can be observed and controlled by monitoring changes in blobs corresponding to the etching process variables.

Dynamic data visualization

A method for determining the endpoint of a plasma etch process is disclosed. The endpoint of the plasma etch process is determined using an acoustic cell attached to an exhaust port on a reaction chamber of a plasma reactor. At least a portion of the gas from the reaction chamber flows into the acoustic cell during the plasma etch process. Acoustic signals are periodically transmitted through the gas flowing in the acoustic cell and a first velocity for the acoustic signals associated with etching a first material layer formed on a substrate is determined. Thereafter, the endpoint of the plasma etch step is determined when the first velocity changes to a second velocity associated with etching the first material layer through its thickness to its interface with an underlying material layer. The gas from the reaction chamber optionally flows through a compressor prior to flowing into the acoustic cell. The compressor increases the pressure of the gas that flows into the acoustic cell.

Plasma etch end point detection process

A process for device fabrication in which polarized light is used to monitor film thickness. The polarized light is made incident on the surface of a substrate with a film thereon that has a different reflectivity than that of the underlying substrate. The surface of the film is non-planar, either by virtue of the fact that the film is formed over a substrate with a non-planar surface, or because there is a patterned layer formed over the film, or both. The substrate is subjected to conditions that change the thickness of the film on the substrate. The polarized light that is reflected from the substrate is detected at a selected wavelength or wavelengths and a trace of the intensity of the reflected light both parallel and perpendicular to the substrate surface over time is obtained. This trace is compared to a model trace which is obtained by approximating the film thickness, and the relative amount of the areas of different reflectivity on the substrate surface. The film thickness used to generate the model trace is adjusted to obtain a desired correspondence between the model trace and the actual trace. When the desired correspondence is obtained, then the film thickness used to obtain the model trace with the desired correspondence is the determined film thickness.

Process for fabricating a device using polarized light to determine film

A non destructive method of spectroscopic ellipsometry adapted to measure the width of features in periodic structures, particularly those features which are less than one micron wide. The method is also adapted to make comparisons between a known reference structure and a sample structure, and to control the fabrication of periodic structures in a plasma etching reactor. Peaks in functions DELTA and PSI versus wavelength are monitored and correlated against reference curves, permitting etching conditions to be modified. This technique avoids the need for use of scanning electron microscopy to measure the linewidth, which is a destructive method. It also posses an advantage over scatterometry which requires several detectors arrayed at different angles from an incident beam to measure the different diffracted orders.

Measurement and control of linewidths in periodic structures using

The present invention is predicated upon the fact that a process signature from a plasma process used in fabricating integrated circuits contains information about phenomena which cause variations in the fabrication process such as age of the plasma reactor, densities of the wafers exposed to the plasma, chemistry of the plasma, and concentration of the remaining material. In accordance with the present invention, a method for using neural networks to determine plasma etch end-point times in an integrated circuit fabrication process is disclosed. The end-point time is based on in-situ monitoring of at least two parameters during the plasma etch process. After the neural network is trained to associate a certain condition or set of conditions with the endpoint of the process, the neural network is used to control the process.

Active neural network determination of endpoint in a plasma etch process

The present invention provides a method and apparatus for monitoring the state of an attribute of a product during the manufacturing process. The invention employs an intelligent system trained in the relationship between the signatures of the manufacturing process and the product attribute as a function of time. In one embodiment the intelligent system comprises two intelligent systems: the first, trained in the relationship between the signatures of the manufacturing process and one or more signatures of the state of the attribute as a function of time; and the second, trained in the relationship between the product-state signatures as a function of time and the product attribute as a function of time. The disclosed apparatus can be an integral part of the manufacturing machinery allowing the process to continue until the exact moment when the desired state is achieved.

Method and apparatus for real time monitoring of wafer attributes in a

An ellipsometric method for process control in the context of device fabrication is disclosed. An ellipsometric signal is used to provide information about the device during the fabrication process. The information is used to better control the process. An ellipsometric signal of a particular wavelength is selected. The signal is selected based on the composition and thickness of the films on the substrate through which the ellipsometric signal will pass before it is reflected from the substrate. Once the appropriate wavelength is determined, the ellipsometric signal is used to monitor the thickness of the films on the substrate over time, to assist in controlling the deposition and removal of films on the substrate, and to perform other process control functions in the context of device fabrication. The ellipsometric method is used to control the deposition and removal of films that underlie patterned masks with aspect ratios of 0.3 or more, that overlie topography on a substrate surface, or that both underlie a mask and overlie topography.

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New York, NY, United States of America

Tseng-Chung Lee