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.