In one aspect, the present invention is a sensor unit for sensing process parameters
of a process to manufacture an integrated circuit using integrated circuit processing
equipment. In one embodiment, the sensor unit includes a substrate having a wafer-shaped
profile and a first sensor, disposed on or in the substrate, to sample a first
process parameter. The sensor unit of this embodiment also includes a second sensor,
disposed on or in the substrate, to sample a second process parameter wherein the
second process parameter is different from the first process parameter. In one
embodiment, the sensor unit includes a first source, disposed on or in the substrate,
wherein first source generates an interrogation signal and wherein the first sensor
uses the interrogation signal from the first source to sample the first process
parameter. The sensor unit may also include a second source, disposed on or in
the substrate, wherein second source generates an interrogation signal and wherein
the second sensor uses the interrogation signal from the second source to sample
the second process parameter. The first sensor and the first source may operate
in an end-point mode or in a real-time mode. In this regard, the first sensor samples
the first parameter periodically or continuously while the sensor unit is disposed
in the integrated circuit processing equipment and undergoing processing. In one
embodiment, the first sensor is a temperature sensor and the second sensor is a
pressure sensor, a chemical sensor, a surface tension sensor or a surface stress sensor.