Vlsi Standards, Inc.

Kla Tencor Corporation

Kla-tencor Technologies Corporation

Ellen R Laird

Bradley W Scheer

Marco Tortonese

James J Greed, Jr

Pat Brady

W Murray Bullis

Jerry Prochazka

Ian R Smith

Rene Blanquies

René M Blanquies

A calibration standard, for calibrating lateral or angular dimensional measurement systems, is provided. The standard may include a first substrate spaced from a second substrate. The standard may be cross-sectioned in a direction substantially perpendicular or substantially non-perpendicular to an upper surface of the first substrate. The cross-sectioned portion of the standard may form a viewing surface of the calibration standard. The standard may include at least one layer disposed between the first and second substrates. The layer, or a feature etched into the first or second substrate or a feature etched into the layer may have a traceably measured thickness or may be oriented at a traceably measured angle with respect to the viewing surface. A thickness or angle of the layer or other feature may be traceably measured using any technique for calibrating a measurement system with a standard reference material traceable to a national testing authority.

Dimensional calibration standards

A calibration standard which may be used to calibrate lateral dimensional measurement systems is provided. The calibration standard may include a first substrate spaced from a second substrate. In addition, the calibration standard may include at least one layer disposed between the first and second substrates. The layer may have a traceably measured thickness. For example, a thickness of the layer may be traceably measured using any measurement technique in which a measurement system may be calibrated with a standard reference material traceable to a national testing authority. The calibration standard may be cross-sectioned in a direction substantially perpendicular to an upper surface of the first substrate. The cross-sectioned portion of the calibration standard may form a viewing surface of the calibration standard. In this manner, a lateral dimensional artifact of the calibration standard may include the traceably measured thickness of at least the one layer.

Submicron dimensional calibration standards and methods of manufacture and use

A method of making and certifying submicron line width calibration standards includes steps of thermal growth of a silicon dioxide film layer on top and vertical side wall surfaces of silicon regions, e.g. strips or mounds, that are formed over a silicon dioxide layer on a silicon substrate, then optically measuring the top film layer thickness, removing the oxide film from the top surface of the silicon regions via a planarization technique that protects the film on the side walls, and finally removing at least some, and in most cases preferably all, of the silicon material to leave just the oxide film that was on the side walls of the former silicon regions as submicron linear features, such as extended isolated lines or connected line segments arranged in a polygon. The width of these linear features is certifiable via cross-section testing of samples that have been formed by the film layer growth by means of scanning electron or atomic force microscopy to obtain a ratio of top-to-side film thicknesses, so that the lines on the standard are determined to have widths calculated from that ratio and the optically measured top film thickness. In an alternate embodiment, an atomic force microscope probe tip determining standard can be made using the same formation steps as the line width standard except that a silicon layer with &lsqb;100&rsqb; top surface instead of &lsqb; &rsqb; top surface for the line width standard is used. Sloping side walls on the silicon regions result so that the oxide film layer will form tilted upwardly projecting blade features when the silicon material is partially removed.

Line width calibration standard manufacturing and certifying method

A method for calibrating topographic instruments, operating at sub-micrometer resolution levels, includes providing a calibration standard having a known one-dimensional power spectral density function. A roughness is calculated from the known one dimensional power spectral density function in relation to an atomic scale topographic dimension, .increment.z.sub.i. The roughness of the calibration standard is measured by detecting light scattering therefrom and computing an isotropic power spectral density curve over the effective spatial bandwidth of the topographic instrument being calibrated. The measured roughness is then compared against the calculated roughness to determine whether the two values of roughness coincide.

Method for calibrating a topographic instrument

A calibration target for topographic inspection instruments, operating at sub-micrometer resolution levels, having features on the order of 10 Angstroms in vertical height, an atomic scale distance. The features are formed on a silicon substrate, such as a wafer, by deposition of a thick oxide, such as a typical thermal oxide, over the wafer surface. A pattern of features is patterned and etched to the level of raw silicon at the wafer surface. Areas which have been etched are converted to a thin oxide, which slightly lowers the level of silicon in these areas. All oxide is removed and the slightly lower level of silicon gives rise to features having atomic scale vertical topographic dimensions. Millions of such features are produced simultaneously on a wafer to mimic the effect of haze or micro-roughness on a polished wafer.

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San Jose, CA, United States of America

Ellen R Laird