http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
An Emissivity-Invariant Condition of Silicon Wafers and Its Application to Radiation Thermometry
Tohru Iuchi,Atsushi Gogami 제어로봇시스템학회 2009 제어로봇시스템학회 국제학술대회 논문집 Vol.2009 No.8
The emissivity behavior of a silicon wafer is simulated using a simple modeling of the spectral, directionaland polarization characteristics of thermal radiation. This study reveals that the p-polarized spectral emissivity of the silicon wafer at a specified direction remains constant. Then, subsequent experiments confirmed the simulated resultsthat the p-polarized emissivity of silicon wafers is maintained to be 0.83 at an angle of 55.4º and a wavelength of 0.9 μm in spite of wide variations in oxide film thickness from 0 to 950 nm, temperature over 900 K as well as resistivity from0.01 to 2000 Ωcm relevant to impurity concentrations doped into the silicon wafer. The overall extended uncertainty (k=2) of the temperature measurement is estimated to be 3.82 K over 900 K at the moment. This result is expected to enable significantly more accurate in situ radiation thermometry of silicon wafers in real manufacturing processes.
Tohru Iuchi,Ryo Shinagawa 제어로봇시스템학회 2008 제어로봇시스템학회 국제학술대회 논문집 Vol.2008 No.10
The temperature dependence on transmittance of a silicon wafer is well known, which is caused by various absorption mechanisms over wide range of spectrum. As the wavelength increases, the photon energy decreases until it becomes smaller than the minimum energy gap in the silicon band structure. At this point there is a rapid drop in absorption, which is often referred to as absorption edge wavelength. The absorption edge shifts to a longer wavelength with increasing temperature because the band gap reduces with increasing temperature. Experiments were carried out from the viewpoints of wavelength (900 ~1700 nm), polarization (p- and s-polarized) and direction (normal to 80º) for specimens with different resistivity (0.01 ~ 2700 Ωcm). A characteristic curve between absorption edge wavelength and temperature is obtained for all of silicon wafers with different resistivity. The results show that this method is promising for in situ temperature measurements of silicon wafers from room to 1000 K at a wavelength where the wafers are semitransparent. In this paper, an experimental apparatus, measurement results and considerations on advantages and disadvantages of this method are described in detail.
Atsushi Gogami,Tohru Iuchi 제어로봇시스템학회 2008 제어로봇시스템학회 국제학술대회 논문집 Vol.2008 No.10
The authors devised a hybrid-type surface temperature sensor that combines the advantage of contact and noncontact method and provide a way to overcome the weak points of both methods. This sensor is composed of two main components: a thin metallic film that makes contact with the object, and an optical sensor that is used to detect the radiance of the rear surface of the film. The temperature measurement using this sensor is possible with an uncertainty of 1 K and the response time within 1 s in the temperature range 600 K to 1000 K. The authors confirmed that this hybrid-type sensor was valid for the in situ temperature monitoring of silicon wafers. By use of this sensor as a calibration device of the surface temperature of a silicon wafer, the authors tried to develop the emissivity compensated radiation thermometry of silicon wafers. An excellent relation between the ratio of polarized radiances and polarized emissivities was found, which is to lead to a promising method for a simultaneous measurement of temperature and emissivity of silicon wafers irrespective of emissivity change. In this paper, experimental results are detailed.