Abrading – Precision device or process - or with condition responsive... – By optical sensor
Patent
1997-11-05
1999-08-10
Scherbel, David A.
Abrading
Precision device or process - or with condition responsive...
By optical sensor
451 5, 451307, B24B 4900
Patent
active
059349743
ABSTRACT:
An in-situ sensor measures polishing pads during chemical mechanical polishing. From the measurements, polishing pads can be identified as worn out or unevenly worn and replaced. Scheduling maintenance according to current measurements, rather than according to statistical predictions, minimizes down time for maintenance and still prevents use of worn out or unevenly worn polishing pads. Alternatively, a tool is reconfigured according to the polishing pad measurements. Reconfiguring the tool can prolong pad life and improve polishing performance. One embodiment of the invention includes a non-contact sensor such as a laser sensor that directs an incident beam at a target area and determines a distance to a reflection point by triangulation of incident and reflected beams. As polishing pads wear, distances to the reflection points increase. Movement of the polishing pads and the sensor during polishing causes the in-situ sensor to measure portions of the polishing pads that are along a zigzag trajectory. When the frequency of the sensor's motion is a multiple of the frequency of revolution of the polishing pads, the sensor retraces the same trajectory after one or more revolutions of the polishing pads. Thus, pad thickness or wear at the same set of points can be compared from one tracing of the trajectory to the next.
REFERENCES:
patent: 5558568 (1996-09-01), Talieh et al.
patent: 5593344 (1997-01-01), Weldon et al.
patent: 5738562 (1998-04-01), Doan et al.
patent: 5762536 (1998-06-01), Pant et al.
patent: 5787595 (1998-08-01), Desai et al.
patent: 5791969 (1998-08-01), Lund
Aplex Group
Millers David T.
Nguyen Dung Van
Scherbel David A.
LandOfFree
In-situ monitoring of polishing pad wear does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with In-situ monitoring of polishing pad wear, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and In-situ monitoring of polishing pad wear will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1113881