Semiconductor metrology​

Accurate, non-contact temperature measurement is critical for advanced silicon microfabrication processes. Our technique leverages the temperature-dependent absorption of silicon in the near-infrared (NIR) range to determine wafer temperature from transmitted optical power. Traditional systems rely on multiple lasers at different wavelengths, which increases complexity and reduces acquisition speed due to switching delays. To address this, we propose a simplified approach using a compact, telecom fiber-based supercontinuum source with a tailored spectrum. Unlike spectrally flat sources, our design features an exponential roll-off towards longer wavelengths, significantly improving temperature accuracy—achieving ∼1 °C precision from room temperature up to 600 °C, a 6× improvement over flat-spectrum sources. The system also eliminates the need for inline optical switches, enabling rapid measurements limited only by detector response time (~66 ms). Moreover, the high power of the supercontinuum source allows easy scalability for parallel, multi-point temperature sensing.