In-situ Si wafer temperature measuring using pulse-modulated infrared laser interferometric thermometry for CVD film deposition

Wafer temperature in high rate and low bias RF boltage SiO2 deposition process was monitored by pulse modulated infrared laser interferometric thermometry. With RF bias, wafer temperature sharply rose to more than 600 degree(s)C due to poor thermal conductivity between a silicon wafer and cooling stage which led to no SiO2 deposition on silicon trenches. However, after improving the thermal conductivity, silicon trenches were successfully filled. Also, temperature dependence of fluorocarbon film deposition on a chamber wall in C4F8/H2 inductively coupled plasma process was investigated. The result implies that wall temperature should be controlled over 300 degree(s)C in order to maintain CFx radical supply on SiO2 surfaces.