Coating processes – Electrical product produced – Integrated circuit – printed circuit – or circuit board
Patent
1995-06-05
1997-04-22
Bareford, Katherine
Coating processes
Electrical product produced
Integrated circuit, printed circuit, or circuit board
427294, 118410, 118679, B05D 512
Patent
active
056227477
ABSTRACT:
A photoresist dispensing apparatus coats a wafer with potoresist to define a layer having substantially uniform thickness. The apparatus receives photoresist into a reservoir. The photoresist flows from the reservoir to a substantially planar channel formed between parallel plates. The photoresist flows between the plates towards an elongated straight-edge exit opening. The surface tension and the viscous forces of the photoresist causes a bead to form at the exit opening. By passing a wafer beneath the dispenser apparatus at the exit opening so as to contact the bead, the surface tension is broken. As a result, the photoresist flows onto the wafer. The wafer is moved under the dispenser on tracks which maintain the wafer substantially level. The pressure from the photoresist in the reservoir maintains a steady flow of photoresist as the wafer passes below the dispenser. Accordingly, a substantially uniform layer of photoresist is applied. Photoresist layers as thin as 20 microns have been achieved. To achieve layers of one micron thickness, a wafer receiving a uniform coating as described above is spun to reduce excess photoresist. As a result, the amount of photoresist applied to a wafer to obtain a one micron layer is substantially reduced. By applying a layer having substantially uniform thickness prior to spinning, streaking and cobweb effects are eliminated.
REFERENCES:
patent: 3707944 (1973-01-01), Grundon et al.
patent: 3811405 (1974-05-01), Baker et al.
patent: 3961599 (1976-06-01), Jones, Jr.
patent: 4225638 (1980-09-01), Waugh
patent: 4281057 (1981-07-01), Castellani et al.
patent: 4291642 (1981-09-01), Kole
patent: 4431690 (1984-02-01), Matt et al.
patent: 4622239 (1986-11-01), Schoenthaler et al.
patent: 4640846 (1987-02-01), Kuo
patent: 4692351 (1987-09-01), Maeda et al.
patent: 4708629 (1987-11-01), Kasamatsu
patent: 4738910 (1988-04-01), Ito et al.
patent: 4744330 (1988-05-01), Claassen
patent: 4794021 (1988-12-01), Potter
patent: 4822647 (1989-04-01), Nozaki et al.
patent: 4833748 (1989-05-01), Zimmer et al.
patent: 4922852 (1990-05-01), Price
patent: 4938994 (1990-07-01), Choinski
patent: 4941428 (1990-07-01), Engel
patent: 4987854 (1991-01-01), Hall
Dyson Frederick
Todd Charles N.
Bareford Katherine
Behiel Arthur J.
National Semiconductor Corporation
Winters Paul J.
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