Apparatus for semiconductor device fabrication diagnosis and prognosis

Abstract

A sensor (210) for diagnosis and prognosis of semiconductor device fabrication processes measures specular, scattered, and total surface reflectances and transmittances of semiconductor wafers (124). The sensor (210) includes a sensor arm (212) and an opto-electronic control box (214), for directing coherent electromagnetic or optical energy in the direction of semiconductor wafer (124). Opto-electronic control box (214) includes circuitry for measuring the amounts of laser powers coherently reflected from and transmitted through the semiconductor wafer (124) surface and the amounts of electromagnetic powers scatter reflected from and transmitted through the semiconductor wafer (124) surface. Specular, scattered, and total reflectance and transmittance as well as surface roughness values for semiconductor wafer (124) are determined based on measurements of coherent and scatter reflected and transmitted laser powers. The sensor (210) can also provide a go/no-go test of semiconductor fabrication process quality. A process control computer associates with the sensor (210) to respond to spectral reflectance and transmittance measurements yielding surface roughness and thickness measurements as well as diagnosis/prognosis analysis results and control signals.

Dependencies are inferred from the claim text.