Browse Prior Art Database

Photoresist Apply and Dry Machine

IP.com Disclosure Number: IPCOM000082611D
Original Publication Date: 1975-Jan-01
Included in the Prior Art Database: 2005-Feb-28
Document File: 5 page(s) / 171K

Publishing Venue

IBM

Related People

Auerbach, IA: AUTHOR [+3]

Abstract

In applying and drying photoresist on semiconductor wafers, especially when dealing with automatic machinery, it is essential that proper clearances exist between the mechanism for transferring the wafer from the input station to the applicator station and ultimately to the bake station, and the arm utilized for dispensing the photoresist onto the wafer.

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Photoresist Apply and Dry Machine

In applying and drying photoresist on semiconductor wafers, especially when dealing with automatic machinery, it is essential that proper clearances exist between the mechanism for transferring the wafer from the input station to the applicator station and ultimately to the bake station, and the arm utilized for dispensing the photoresist onto the wafer.

Referring to Fig. 1 there is shown a schematic plan view of a typical photoresist applicator and dryer 10. A conventional conveyor 11 moves semiconductor wafers into a loading station 12, whereat the wafers are picked up and deposited on or into one of two photoresist applicator stations 13 or 14, respectively. The semiconductor wafers are picked up by one of the boomerang shaped wafer transport arms 15 and 16, which are coupled to a central indexing shaft 17.

The wafers are also moved from the apply stations 13 and 14 by one or other of the arms 15 and 16 onto a hot plate 18 for drying the photoresist on the wafer, while arm 19 serves to remove the wafers from the hot plate 18 onto an unload station 20, associated with an unload conveyor 21.

Additionally, each of the apply stations 13 and 14 includes a photoresist applicator arm 13A and 14A, respectively, which must swing across the wafer and deposit photoresist thereon for spinning of the wafer within a wafer cup, not shown, at the apply station. It is essential that at the time the applicator arms 13A and 14A move into position superimposed over the spin cups that the transfer arms 15 and 16 are not at their idle position over the wafer cups, but instead are at least in an elevated position so that jamming or smashups between the photoresist applicator arms 13A, 14A and the transfer arms 15, 16 does not occur.

Referring to Fig. 4, a constant-speed motor 25 is coupled to a gear 2, and also via the meshing teeth of the gear 2 to a second gear 1. Each of the gears includes a single-revolution clutch designated A and B, respectively, the gear teeth of which are coupled to an input drive gear 5. When the single-revolution clutch associated with the gear 2 is picked, the gear 5 rotates in the direction of arrow A and when the clutch associated with gear 1 is picked, the input gear 5 rotates in the direction of the arrow designated B.

The input gear 5 is connected to a star wheel or a four point epicycloidal gear, in which 360 degrees rotation of the gear effects a 90 degrees rotation of the splined output shaft 17. The input gear 5 is also coupled by a belt 7 to suitable gearing 8 and then to a box cam 9. Rotation of the shaft 17 causes rotation of the transfer arms 15 and 16 (only one of which is shown in the drawing). The purposes of the box cam 9 is to effect rotation of a yoke 25 about a pivot 26 by the action of the cam 9 rotating against the follower 27.

As shown, the yoke 25 is connected, by suit...