SIMULTANEOUS INSITU MEASUREMENT OF FILM THICKNESS AND TEMPERATURE BY USING MULTIPLE WAVELENGTHS PYROMETRIC INTERFEROMETRY (MWPI)

Film thickness and temperature are two of the most important quantitie s in semiconductor manufacturing. They play a fundamental role in many standard production techniques like chemical vapor deposition (CVD, L PCVD, PECVD), thermal oxidation and diffusion. They are especially imp ortant for more recently developed technologies like molecular beam ep itaxy (MBE), metal organic MBE (MOMBE), metal organic CVD (MOCVD), che mical beam epitaxy (CBE), etc. In this paper, an optical in situ metho d for simultaneous film thickness and temperature measurements-named M ultiple Wavelengths Pyrometric Interferometry (MWPI)-is introduced, wh ich is capable of high resolution (up to 0.1 nm for thickness and 0.02 5 K for temperature) and for real time data evaluation. It can be used for process control as well as in situ quality inspection without tim e delay or additional handling mechanisms and is suitable for monitori ng single films as well as multilayer structures. MWPI is insensitive to vibration, rotation and misalignment of the wafer. Due to its optic al basis it is also insensitive to hostile environments like high temp erature and/or chemical reactive gases. The physical basis of MWPI is outlined as well as the necessary steps of the evaluation procedure. T he simultaneous in situ MWPI film thickness and temperature measuremen t during the thermal oxidation of Si is presented. The potential techn ical impact of MWPI on automation, reliability and long term performan ce of semiconductor manufacturing is discussed.