Rapid-Response Hybrid-Type Surface-Temperature Sensor

Abstract

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.

Simultaneous measurement of emissivity and temperature of silicon wafers using a polarization technique

“…Fig. 5 shows a schematic diagram of the newly developed hybrid surface temperature sensor [10]. This sensor was based on the assumption that the temperature of the thin film was spatially uniform at any instant during the transient process [15].…”

“…In order to perform these experiments, a user-friendly hybrid surface temperature sensor developed by the authors was used for temperature calibration of the silicon wafers [10].…”

Uncertainty of a hybrid surface temperature sensor for silicon wafers and comparison with an embedded thermocouple

“…Then, the surface temperature of the specimen can be accurately determined. 4,5 The first version of the hybrid surface sensor required a response time of several tens of seconds, and the measurement was limited to the temperature range from 900 to 1000 K. 4 Then, an improved version of this sensor having a rapid response of within 1 s was developed. 5 The uncertainty in the improved sensor was estimated to be 0.5 K as the evaluation was restricted only to the fluctuation of temperature readings of the hybrid surface sensor.…”

“…5 There is always a difference, ⌬T h ͑=T s − T f ͒, between the surface temperature T s of the object and T f . Under the constant contact pressure ͑40 kPa͒ of the film on the object, ⌬T h is treated as the known systematic error with uncertainty u h .…”

“…Heat-resistant blackbody coating was painted onto the silicon wafer. 4,5 The reading by the monitoring radiometer ͑IR-FBWS-SP, CHINO͒ is assumed to be the true surface temperature T s , with a combined standard uncertainty u M that is caused in part by the uncertainty of the effective emissivity of the blackbody coating. We assume that fluctuates within Ϯ⌬, which results in temperature fluctuation u , which is given as follows: where is the wavelength ͑m͒ and T is the temperature ͑K͒.…”