Boxer Cross, Inc

Applied Materials, Inc.

Other

Regina G Nijmeijer

Peter G Borden

Jiping Li

Beverly J Klemme

A coefficient of a function that relates a measurement from a wafer to a parameter used in making the measurement (such as the power of a beam used in the measurement) is determined. The coefficient is used to evaluate the wafer (e.g. to accept or reject the wafer for further processing), and/or to control fabrication of another wafer. In one embodiment, the coefficient is used to control operation of a wafer processing unit (that may include, e.g. an ion implanter), or a heat treatment unit (such as a rapid thermal annealer).

Use of coefficient of a power curve to evaluate a semiconductor wafer

A method (1) creates charge carriers in a concentration that changes in a periodic manner (also called 'modulation') only with respect to time, and (2) determines the number of charge carriers created in the carrier creation region by measuring an interference signal obtained by interference between a reference beam and a portion of a probe beam that is reflected by charge carriers at various depths of the semiconductor material, and comparing the measurement with corresponding values obtained by simulation (e.g. in graphs of such measurements for different junction depths). Various properties of the reflected portion of the probe beam (such as power and phase) are functions of the depth at which the reflection occurs, and can be measured to determine the depth of the junction, and the profile of active dopants. Therefore, the just-described reflected portion of the probe beam is interfered with a reference beam formed by a portion of probe beam reflected by the front surface of the semiconductor material, and phase and amplitude of the interference signal resulting therefrom are both measured. Alternatively, a phase difference between a first interference signal (obtained by interference of (1) a variable phase beam and (2) the portion of probe beam reflected by the front surface) and a second interference signal (obtained by interference of (1) the variable phase beam and (2) a portion of the probe beam reflected by charge carriers at various depths) indicates the junction depth.

Apparatus and method for determining the active dopant profile in a semiconductor wafer

Use of a coefficient of a power curve to evaluate a semiconductor wafer

An apparatus and method uses diffusive modulation (without generating a wave of carriers) for measuring a material property (such as any one or more of: mobility, doping, and lifetime) that is used in evaluating a semiconductor wafer. The measurements are carried out in a small area, for use on wafers having patterns for integrated circuit dice. The measurements are based on measurement of reflectance, for example as a function of carrier concentration. In one implementation, the semiconductor wafer is illuminated with two beams, one with photon energy above the bandgap energy of the semiconductor, and another with photon energy near or below the bandgap. The diameters of the two beams relative to one another are varied to extract additional information about the semiconductor material, for use in measuring, e.g. lifetime.

Apparatus and method for evaluating a semiconductor wafer

A method (1) creates charge carriers in a concentration that changes in a periodic manner (also called &ldquo;modulation&rdquo;) only with respect to time, and (2) determines the number of charge carriers created in the carrier creation region by measuring an interference signal obtained by interference between a reference beam and a portion of a probe beam that is reflected by charge carriers at various depths of the semiconductor material, and comparing the measurement with corresponding values obtained by simulation (e.g. in graphs of such measurements for different junction depths). Various properties of the reflected portion of the probe beam (such as power and phase) are functions of the depth at which the reflection occurs, and can be measured to determine the depth of the junction, and the profile of active dopants. Therefore, the just-described reflected portion of the probe beam is interfered with a reference beam formed by a portion of probe beam reflected by the front surface of the semiconductor material, and phase and amplitude of the interference signal resulting therefrom are both measured. Alternatively, a phase difference between a first interference signal (obtained by interference of (1) a variable phase beam and (2) the portion of probe beam reflected by the front surface) and a second interference signal (obtained by interference of (1) the variable phase beam and (2) a portion of the probe beam reflected by charge carriers at various depths) indicates the junction depth.

A method (1) creates charge carriers in a concentration that changes in a periodic manner (also called &ldquo;modulation&rdquo;) only with respect to time, and (2) determines the umber of charge carriers created in the carrier creation region by measuring an interference signal obtained by interference between a reference beam and a portion of a probe beam that is reflected by charge carriers at various depths of the semiconductor material, and comparing the measurement with corresponding values obtained by simulation (e.g. in graphs of such measurements for different junction depths). Various properties of the reflected portion of the probe beam (such as power and phase) are functions of the depth at which the reflection occurs, and can be measured to determine the depth of the junction, and the profile of active dopants. Therefore, the just-described reflected portion of the probe beam is interfered with a reference beam formed by a portion of probe beam reflected by the front surface of the semiconductor material, and phase and amplitude of the interference signal resulting therefrom are both measured. Alternatively, phase difference between a first interference signal (obtained by interference of (1) a variable phase beam and (2) the portion of probe beam reflected by the front surface) and a second interference signal (obtained by interference of (1) the variable phase beam and (2) a portion of the probe beam reflected by charge carriers at various depths) indicates the junction depth.

A method (,) creates charge carriers in a concentration that changes in a periodic manner (also called &ldquo;modulation&rdquo;) only with respect to time, and (,) determines the number of charge carriers created in the carrier creation region by measuring an interference signal obtained by interference between a reference beam and a portion of a probe beam that is reflected by charge carriers at various depths of the semiconductor material, and comparing the measurement with corresponding values obtained by simulation (e.g. in graphs of such measurements for different junction depths). Various properties of the reflected portion of the probe beam (such as power and phase) are functions of the depth at which the reflection occurs, and can be measured to determine the depth of the junction, and the profile of active dopants. Therefore, the just-described reflected portion of the probe beam is interfered with a reference beam formed by a portion of probe beam reflected by the front surface of the semiconductor material, and phase and amplitude of the interference signal resulting therefrom are both measured. Alternatively, a phase difference between a first interference signal (obtained by interference of (,) a variable phase beam and (,) the portion of probe beam reflected by the front surface) and a second interference signal (obtained by interference of (,) the variable phase beam and (,) a portion of the probe beam reflected by charge carriers at various depths) indicates the junction depth.

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Campbell, CA, United States of America

Regina G Nijmeijer