Process for chemical-mechanical polishing of III-V semiconductor materials
End point detection method for physical etching process
Apparatus for automatic lapping control
Method for machining workpieces of brittle hard material into wafers
In situ conductivity monitoring technique for chemical/mechanical planarization endpoint detection
Counterbalanced polishing apparatus
Integrated circuit planarization by mechanical polishing
ApplicationNo. 686686 filed on 04/17/1991
US Classes:451/1, PRECISION DEVICE OR PROCESS - OR WITH CONDITION RESPONSIVE CONTROL216/38, PLANARIZING A NONPLANAR SURFACE216/84, With measuring, testing, or inspecting257/E21.244, Involving dielectric removal step (EPO)438/692, Simultaneous (e.g., chemical-mechanical polishing, etc.)438/959, MECHANICAL POLISHING OF WAFER451/41, Glass or stone abrading451/287Planar surface abrading
ExaminersPrimary: Parker, Roscoe V.
Attorney, Agent or Firm
International ClassesB24B 049/16
AbstractAn apparatus for detecting a planar endpoint on a semiconductor wafer during mechanical planarization of the wafer. The planar endpoint is detected by sensing a change in friction between the wafer and a polishing surface. This change of friction may be produced when, for instance, an oxide coating of the wafer is removed and a harder material is contacted by the polishing surface. In a preferred form, the change in friction is detected by rotating the wafer and polishing surface with electric motors and measuring current changes on one or both of the motors. This current change can then be used to produce a signal to operate control means for adjusting or stopping the process.