US 5,255,286 A · Multi-point pyrometry with real-time surface emissivity compensation

Abstract

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.

Claims30

Dependent claims

A multi-point non-invasive, real-time pyrometry-based sensor apparatus for simultaneously measuring radiance of a semiconductor wafer in a fabrication reactor and compensating for wafer emissivity, comprising:

a laser source for emitting a beam of light;
a beam splitter module for receiving said beam, splitting said beam into a plurality of split beams, and simultaneously directing said split beams as incident beams to selected areas of the surface of the semiconductor wafer;
circuitry means for receiving a plurality of reflected beams caused by reflection of said incident beams from said wafer and for receiving incoherent radiant energy emitted by the semiconductor wafer;
circuitry means for detecting and processing said incident beams, said reflected beams and said incoherent radiant energy, for converting detected signals of said incident and reflected beams to values for semiconductor wafer emissivity and for converting said incoherent radiant energy into semiconductor wafer radiance measurements;
and
circuitry means for achieving real-time semiconductor wafer temperature measurements based on said emissivity values and radiance measurements.

3 more elements

A real-time, non-invasive, in-situ sensor apparatus for temperature measurement of a heated semiconductor wafer, comprising:

an electromagnetic energy source for simultaneously directing a plurality of incident coherent beams of electromagnetic energy to the surface of the semiconductor wafer;
circuitry means for collecting a plurality of reflected coherent beams of electromagnetic energy resulting from the reflection of said plurality of incident coherent beams from the semiconductor wafer;
circuitry means for collecting incoherent radiant energy emitted rom a plurality of points on said heated semiconductor wafer;
circuitry means for calculating temperature values for the semiconductor wafer as a function of said plurality of incident and reflected coherent beams and said incoherent radiant energy;
and
circuitry means for measuring the surface roughness of the semiconductor wafer and for calculating emissivity and temperature values for the semiconductor wafer as a function of said plurality of incident and reflected coherent beams, said incoherent radiant energy, and said surface roughness.

3 more elements

Dependencies are inferred from the claim text.

Multi-point pyrometry with real-time surface emissivity compensation

Life of this patent

Multi-point pyrometry with real-time surface emissivity compensation

Life of this patent

Abstract

Claims30