Therma-wave, Inc.

Kla Tencor Corporation

Therma-wave Partners

Walter Lee Smith

Allan Rosencwaig

Jon Opsal

David M Aikens

Youxian Wen

David L Willenborg

Clifford G Wells

An optical metrology includes a library, a metrology tool and a library evolution tool. The library is generated to include a series of predicted measurements. Each predicted measurement is intended to match the measurements that a metrology device would record when analyzing a corresponding physical structure. The metrology tool compares its empirical measurements to the predicted measurements in the library. If a match is found, the metrology tool extracts a description of the corresponding physical structure from the library. The library evolution tool operates to improve the efficiency of the library. To make these improvements, the library evolution tool statistically analyzes the usage pattern of the library. Based on this analysis, the library evolution tool increases the resolution of commonly used portions of the library. The library evolution tool may also optionally reduce the resolution of less used portions of the library.

Evolution of library data sets

An apparatus for scatterometry measurements is disclosed. The apparatus includes a modulated pump source for exciting the sample. A separate probe beam is directed to interact with the sample and the modulated optical response is measured. The measured data is subjected to a scatterometry analysis in order to evaluate geometrical sample features that induce light scattering.

Modulated scatterometry

A combination metrology tool is disclosed for analyzing samples, and in particular semiconductor samples. The device includes a first measurement module for determining electrical characteristics of the sample. In general, such a measurement module will monitor electrical characteristics to derive information such as carrier lifetimes, diffusion lengths and surface doping. The device also includes a second measurement module for determining compositional characteristics such as layer thickness, index of refraction and extinction coefficient. The second measurement module will include a light source for generating a probe beam which interacts with the sample. A detection system is provided for monitoring either the change in magnitude or polarization state of the probe beam. The output signals from both measurement modules are combined by a processor to more accurately evaluate the sample.

Combination optical and electrical metrology apparatus

The use of scatterometry measurements is proposed for the evaluation of the implantation or annealing of dopants in a semiconductor. In accordance with the subject method, a probe beam of light illuminates the wafer having the dopants implanted therein. The light reflected from the sample is measured and subjected to a scatterometry analysis. The information derived is correlated to the implant region so that parameters of the implant, such as depth of a junction and lateral spreading of the implant or the dose of implanted ions can be evaluated.

Scatterometry for junction metrology

A combination metrology tool is disclosed for analyzing samples, and in particular semiconductor samples. The device includes a first measurement module for determining electrical characteristics of the sample. In general, such a measurement module will monitor voltage or capacitance characteristics to derive information such as carrier lifetimes, diffusion lengths and surface doping. The device also includes a second measurement module for determining compositional characteristics such as layer thickness, index of refraction and extinction coefficient. The second measurement module will include a light source for generating a probe beam which interacts with the sample. A detection system is provided for monitoring either the change in magnitude or polarization state of the probe beam. The output signals from both measurement modules are combined by a processor to more accurately evaluate the sample.

Systems and methods for improved metrology using combined optical and electrical measurements

An apparatus is disclosed for evaluating thermal and electrical characteristics of a sample. An intensity modulated pump beam is focused onto the surface of a sample at one spot. A non-modulated probe beam is focused onto the sample at a second spot, spaced laterally and vertically from the first spot. The distance between the two spots is at least two microns. The modulated power of the reflected probe beam that is in phase with the pump beam modulation frequency is monitored to provide information about the characteristics of the sample. The apparatus is particularly useful in evaluating the integrity of metal lines and vias in a semiconductor sample.

Apparatus for evaluating thermal and electrical characteristics in a

A method and apparatus are disclosed for evaluating surface and subsurface features in a semiconductor sample. In operation, a periodic energy source is applied to the surface of the semiconductor sample to generate a periodic electron-hole plasma. This plasma interacts with features in the sample as it diffuses. The plasma affects the index of refraction of the sample and the changing plasma density is monitored using a radiation probe. In the preferred embodiment, the radiation probe measures the plasma induced periodic changes of reflectivity of the surface of the sample to yield information about the sample, such as ion dopant concentrations, residue deposits and defects.

Method and apparatus for evaluating surface and subsurface and

Method and apparatus for evaluating surface and subsurface features in a

A method and apparatus is disclosed for detecting defect surface states in any material and in particular semiconductors. In the subject device, a periodic localized excitation is generated at the surface of the sample with an intensity modulated pump laser beam. A probe laser beam is directed to the surface of the sample and changes in the probe beam which are in phase with the modulated pump frequency are detected. In the preferred embodiment, periodic changes in the optical reflectivity of the surface of the sample induced by an intensity modulated excitation beam are detected by measuring the corresponding modulations in the reflected power of the probe beam. Any time dependence of the probe beam modulated reflectance signal is monitored. An evaluation of defect surface states is then made by investigating the time dependence of the magnitude and/or phase of this probe beam modulated reflectance signal.

Method and apparatus for optically detecting surface states in materials

An apparatus and method is disclosed for evaluating surface conditions on a sample. The system is particularly suited for detecting thin residues encountered in semiconductor lithographic and etching processes. The system is also capable of measuring ion implanted dopant concentrations prior to annealing. The apparatus includes an intensity modulated laser beam which is focused on the surface of the sample to generate periodic heating. A second light beam is focused onto the periodically heated area of the sample in a manner such that it is reflected to a detector. The intensity changes in the probe beam, resulting from the temperature induced changes of reflectivity at the surface of the sample, are measured and evaluated to determine the absence or presence of residues, or to measure the concentrations of ion implanted dopants.

Method and apparatus for evaluating surface conditions of a sample

A method and apparatus is disclosed for detecting thermal waves. This system is based on the measurement of the change in reflectivity at the sample surface which is a function of the changing surface temperature. The apparatus includes a radiation probe beam that is directed on a portion of the area which is being periodically heated. A photodetector is aligned to sense the intensity changes in the reflected radiation probe beam which results from the periodic heating. These signals are processed to detect the presence of thermal waves.

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Danville, CA, United States of America

Walter Lee Smith