Abrasive tool making process – material – or composition – With carbohydrate or reaction product thereof
Patent
1992-04-09
1993-09-21
Rachuba, M.
Abrasive tool making process, material, or composition
With carbohydrate or reaction product thereof
5116576, 5116588, 511313, B24B 4100
Patent
active
052457940
ABSTRACT:
An apparatus for detecting a polishing endpoint during chemical-mechanical planarization/polishing of a wafer senses an acoustic wave generated by rubbing contact between a polish pad and a hard surface underlying a softer material being removed. The apparatus includes a transducer for converting the acoustic wave energy in the range of 30 to 100 Hertz into an audio signal. The audio signal is processed by a low pass cutoff filter to remove high frequency noise. The filtered audio signal is supplied to a phase lock loop to detect a predetermined audio frequency and, in response, provide a logic signal to an integrator. The integrator integrates the logic signal over time to eliminate transient noise spikes, and supplies a detection signal only upon receiving the logic signal for a predetermined period. The detection signal starts a counter to provide a predetermined overpolishing time prior to termination of polishing operations.
REFERENCES:
patent: 3841031 (1974-10-01), Walsh
patent: 4193226 (1980-03-01), Gill, Jr. et al.
patent: 4358338 (1982-11-01), Downey et al.
patent: 4462860 (1984-07-01), Szmanda
patent: 4680893 (1987-07-01), Cronkhite et al.
patent: 4687539 (1987-08-01), Burns et al.
patent: 4693036 (1987-09-01), Mori
patent: 4695700 (1987-09-01), Provence et al.
patent: 4717446 (1988-01-01), Nagy et al.
patent: 4767495 (1988-08-01), Nishioka
patent: 4793895 (1988-12-01), Kaanta et al.
patent: 4811522 (1989-03-01), Gill, Jr.
patent: 4846920 (1989-07-01), Keller et al.
patent: 4948259 (1990-09-01), Enke et al.
patent: 4953982 (1990-09-01), Ebbing et al.
patent: 4954212 (1990-09-01), Gabriel et al.
patent: 4975141 (1990-12-01), Greco et al.
patent: 4998021 (1991-03-01), Mimasaka
patent: 5036015 (1991-07-01), Sandhu et al.
patent: 5045149 (1991-09-01), Nulty
patent: 5069002 (1991-12-01), Sandhu et al.
patent: 5081796 (1992-01-01), Schultz
patent: 5122481 (1992-06-01), Nishiguchi
Advanced Micro Devices , Inc.
Rachuba M.
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