Multi-point pyrometry with real-time surface emissivity compensation

摘要

A multi-point non-invasive, real-time pyrometry-based temperature sensor (200) for simultaneously sensing semiconductor wafer (22) temperature and compensating for wafer emissivity effects. The pyrometer (200) measures the radiant energy that a heated semiconductor wafer (22) emits and coherent beams of light (224) that the semiconductor wafer (22) reflects. As a result, the sensor (200) generates accurate, high-resolution multi-point measurements of semiconductor wafer (22) temperature during a device fabrication process. The pyrometer (200) includes an infrared laser source (202) that directs coherent light beam (203) into beam splitter (204). From the beam splitter (204), the coherent light beam (203) is split into numerous incident coherent beams (210). Beams (210) travel via optical fiber bundles (218) to the surface of semiconductor wafer (22) within the fabrication reactor (80). Each optical fiber bundle (218) collects reflected coherent light beam and radiant energy from wafer (22). Reflected coherent light beam (226) and radiant energy (222) is directed to a detector (240) for detecting signals and recording radiance, emissivity, and temperature values. Multiple optical fiber bundles (218) may be used in the sensor (200) for high spatial resolution multi-point measurements of wafer (22) temperature for precision real-time process control and uniformity optimizations.