Patent ID: 6609947
Filing Date: 2003-08-26
Classification: B24B,B24D

Abstract:
A system for controlling a mechanical or chemical-mechanical planarizing machine that planarizes microelectronic substrates, comprising:a light system having a light source comprising at least a first emitter that generates a first light pulse having a first color and a second emitter that generates a second light pulse having a second color different than the first color, wherein the light source is configured to direct the first and second light pulses toward a front surface of a microelectronic substrate in a manner that creates a first return light pulse corresponding to a reflectance of the first light pulse and a second return light pulse corresponding to a reflectance of the second light pulse; a sensor configured to receive the first return light pulse and the second return light pulse, the sensor being capable of generating a first measured intensity of the first return light pulse and a second measured intensity of the second return light pulse; and a computer coupled to the sensor, the computer having a database and a computer readable medium, the database containing a plurality of sets of reference reflectances in which each set has a first reference component defined by a reflectance intensity of the first light pulse and a second reference component defined by a reflectance intensity of the second light pulse from a selected surface level in a layer of material on the microelectronic substrate, and the computer readable medium containing a computer readable program that causes the computer to control a parameter of the planarizing machine when the first and second measured intensities correspond to the first and second reference components of a selected reference reflectance set.