A photoemission electron microscopy having a light source system for carrying out a high-resolution measurement such as work function distribution measurement or magnetic domain distribution with reliability, and a high-sensitivity measurement method using the photoemission electron microscopy. A photoemission electron microscopy having an excitation light source system in which a specimen is irradiated with irradiation light from a light source uses a vacuum chamber in which the specimen is placed and an objective lens which collects the irradiation light on a specimen surface. The objective lens is accommodated in the vacuum chamber. The light source may be placed outside the vacuum chamber. A condenser lens which makes the irradiation light from the light source generally parallel may be placed between the light source and the vacuum chamber. A transmission window which transmits the irradiation light while the vacuum chamber is sealed may be placed between the condenser lens and the objective lens. If a diffraction grating for selecting the wavelength of the irradiation light or a polarizing filter for selecting the direction of circularly polarized light in the irradiation light is used between the condenser lens and the transmission window, a high-resolution measurement of a work function distribution or a magnetic domain distribution on the specimen surface can be carried out.

The present invention pertains to techniques for increasing the available illumination light, increasing the resolution, and optimizing the spectrum of optical inspection systems. These techniques involve combining the light beams from two or more separate illumination sources. In one embodiment, this performed by utilizing two separate illumination sources wherein one of the illumination sources compensates the other illumination source in the wavelength range where illumination light intensity is low. Specifically, this can be performed by utilizing a broadband illumination source and a narrowband illumination source combined with dichroic beamsplitters.

Systems and methods are disclosed for evaluating nitrogen levels in thin gate dielectric layers formed on semiconductor samples. In one embodiment, a tool is disclosed which includes both a narrow band ellipsometer and a broadband spectrometer for measuring the sample. The narrowband ellipsometer provides very accurate information about the thickness of the thin film layer while the broadband spectrometer contains information about the nitrogen levels. In another aspect of the subject invention, a thermal and/or plasma wave detection system is used to provide information about the nitrogen levels and nitration processes.

A method of determining optical constants n and k for a film on a substrate is described. Optical measurements are preferably performed with an integrated optical measurement system comprising a reflectometer, spectral ellipsometer, and broadband spectrometer such as an Opti-Probe series tool from Therma-Wave. A beam profile reflectometer is employed to first determine the thickness of said film from a best fit of modeling data to experimental data. The thickness data is combined with the ellipsometer and spectrometer measurements to produce an experimental data output which is fitted with modeled information to determine a best fit of the data. Constants n and k are derived from the best fit of data. The method provides a higher accuracy for n and k values than by standard procedures which calculate n, k, and t simultaneously. The method may also be applied to bilayer or multi-layer film stacks.

One embodiment of the present invention is a method for characterizing an electron beam treatment apparatus that includes: (a) e-beam treating one or more of a predetermined type of wafer or substrate utilizing one or more sets of electron beam treatment para meters; (b) making post-electron beam treatment measurements of intensity of a probe beam reflected from the surface of the one or more wafers in which thermal and/or plasma waves have been induced; and (c) developing data from the post-electron beam treatment measurements that provide insight into performance of the electron beam treatment apparatus.