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Browse Prior Art Database

Dark Etch Station

IP.com Disclosure Number: IPCOM000082986D
Original Publication Date: 1975-Mar-01
Included in the Prior Art Database: 2005-Feb-28
Document File: 2 page(s) / 36K

Publishing Venue

IBM

Related People

Edel, WA: AUTHOR [+2]

Abstract

Sometimes there is a need to etch semiconductor wafers in total darkness. In the past, operators manually etched in a darkroom. Shown is a dark etch station where all the operator does is place the wafers in a light-proof box, close the cover, and set the timing for each sequence step. The equipment then automatically etches and rinses the wafers in total darkness.

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Dark Etch Station

Sometimes there is a need to etch semiconductor wafers in total darkness. In the past, operators manually etched in a darkroom.

Shown is a dark etch station where all the operator does is place the wafers in a light-proof box, close the cover, and set the timing for each sequence step. The equipment then automatically etches and rinses the wafers in total darkness.

Wafers are placed in the lightproof etch/rinse tank 4, and the cover 5 is placed on the tank. Diluted HF acid is pumped by pump 6 from large HF acid hold tank 8 until the wafers are completely submerged. When the etch time is completed, the HF acid is drained through HF drain 10. The wafers are then DI water spray rinsed through nozzles 12 by source 14.

The HF supply line is DI water flushed by opening valve 18 prior to closing the drain valve 11. The check valve 22 prevents the DI water from entering the HF holding tank 8. Then the wafers are DI water overflow rinsed through valve 18 and drained through passage 19 into drain 20, with drain valves 15 and 11 closed.

After the overflow rinse, the tank 4 is drained through valve 15 into drain 20. The rinse cycle can be repeated automatically for any number of programmed cycles.

The wafers are removed from the etch/rinse tank 4 for spin drying after the last overflow rinse cycle.

The acid holding tank is filled through fill tube 24.

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