Emissivity modeling of metals has been developed to elucidate behavior during the growth of oxide film, and the modeling results have been compared with experimental results. To express emissivities, pseudo-optical constants of a bare metal and of an oxide film obtained by an elipsometer are substituted into the model equations. Emissivity behavior during the growth of an oxide film upon the surface of a specimen is shown in terms of spectral, directional, and polarized characteristics, and it coincides with the experimental results, both quantitatively and qualitatively. The modeling is simple and provides useful guidance for the development of emissivity-compensated radiation thermometry.

An apparatus of the radiometric emissivity measurement of a metal has been developed. The apparatus possesses some features that it can keep a metallic sample under specific conditions such as vacuum, oxidizing, and deoxidizing atmosphere. Using the apparatus, spectral (from visible to 10 μm infrared wavelengths), directional (normal and 80°), and polarized emissivities (p and s polarized) of metals can be measured and can be utilized to investigate the behavior of the emissivity of the specimen. In this article, the concrete design of the apparatus is described and some examples of measurements of emissivities under some specific conditions are introduced. The peculiar behaviors of the emissivity of a metal in the early stage when the oxide film is grown on its surface are discussed.

A nonconstact technique for reducing the core loss of a grain oriented silicon steel has been developed by the use of Q-switched laser irradiation. Vaporization of the surface layer of the silicon steel by the laser irradiation induced a stress which resulted in a refinement of 180° domain wall spacing. This phenomenon reduced the core loss of the steel. It was found that the laser irradiation was more effective in a specimen with a higher magnetic induction and the core loss reduced by more than 10% under the optimum condition of the laser irradiation. Since the laser processing is a noncontact technique, it is easily applicable to the production line of the silicon steel.

A hybrid-type surface-temperature sensor that combines the advantages of contact and non-contact sensing methods has been developed and that offers a way to overcome the weak points of both methods. The hybrid-type surface-temperature sensor is composed of two main components: a metal film that makes contact with the object and an optical sensor that is used to detect the radiance of the rear surface of the metal film. Temperature measurement using this thermometer is possible with an uncertainty of 0.5 K after compensating for systematic errors in the temperature range from 900 to 1,000 K. The response time of our previous hybrid-type sensor is, however, as long as several tens of seconds because the measurement must be carried out under thermally steady-state conditions. In order to overcome this problem, a newly devised rapid-response hybrid-type surface-temperature sensor was developed and that can measure the temperature of an object within 1 s by utilizing its transient heat transfer response. Currently, the temperature of a silicon wafer can be measured with an uncertainty of 1.0 K in the temperature range from 900 to 1,000 K. This sensor is expected to provide a useful means to calibrate in situ temperature measurements in various processes, especially in the semiconductor industry. This article introduces the basic concept and presents experimental results and discussions.

We have developed a user-friendly hybrid surface temperature sensor. The uncertainties of temperature readings associated with this sensor and a thermocouple embedded in a silicon wafer are compared. The expanded uncertainties (k=2) of the hybrid temperature sensor and the embedded thermocouple are 2.11 and 2.37 K, respectively, in the temperature range between 600 and 1000 K. In the present paper, the uncertainty evaluation and the sources of uncertainty are described.

An emissivity-invariant condition for a silicon wafer was determined by simulation modeling and it was confirmed experimentally. The p-polarized spectral emissivity at a wavelength of 900 nm and at temperatures over 900 K was constant at 0.83 at an angle of about 55.4° irrespective of large variations in the oxide layer thickness and the resistivity due to the different impurity doping concentrations of the silicon wafer. The expanded uncertainty, U(c) = ku(c) (k = 2), of the temperature measurement is estimated to be 4.9 K. This result is expected to significantly enhance the accuracy of radiometric temperature measurements of silicon wafers in actual manufacturing processes.

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A hybrid-type surface temperature sensor combines the contact and noncontact methods, which allows us to overcome the shortcomings of both methods. The hybrid-type surface thermometer is composed mainly of two components: a metal film sheet that makes contact with an object and a radiometer that is used to detect the radiance of the rear surface of the metal film, which is actually a modified radiation thermometer. Temperature measurement using the hybrid-type thermometer with a several tens micrometer thick Hastelloy sheet, a highly heat and corrosion resistant alloy, is possible with a systematic error of −0.5K and random errors of ±0.5K, in the temperature range from 900to1000K. This thermometer provides a useful means for calibration of in situ temperature measurement in various processes, especially in the silicon semiconductor industry. This article introduces the basic idea of the hybrid-type surface sensor, presents experimental results and discussions, and finally describes some applications.