| abstract |
In an apparatus for removing material from an article, such as an exposed surface of an intermediate integrated circuit structure, by planarizing, polishing, etching or the like, a sensor is mechanically coupled to a moving carrier of the article for directing through the article to its first side an electromagnetic radiation beam having a wavelength band to which the structure is substantially transparent. The beam is detected after interacting with the article, such as being reflected from its exposed surface, and resulting information of the state of the processing of the exposed surface is transmitted from the moving carrier to a stationary receiver by radiation without the use of any physical transmission media such as wires or optical fibers. Multiple sensors mounted on the moving article carrier provide information of the uniformity of the processing across the exposed article surface. The radiation signal received by the stationary receiver is used to monitor or control the processing, such as by determining an endpoint thereof. |