Browse Prior Art Database

Redesign of Furnaces Used in Semiconductor Production Lines

IP.com Disclosure Number: IPCOM000039252D
Original Publication Date: 1987-May-01
Included in the Prior Art Database: 2005-Feb-01
Document File: 2 page(s) / 51K

Publishing Venue

IBM

Related People

Muller-Landau, F: AUTHOR

Abstract

A change in the flow of the purging gas mixture used in semiconductor production furnace has been proposed which would prevent outgassing contaminants from depositing on substrates, modules and wafers going through the furnace. The modification would introduce the gas supply into the cooler end zones and exhaust it in the hottest zone, which is opposite from the previous flow pattern. In experiments with a quartz tube simulating the gas flow, it was found that where the temperature range of a furnace allows initial sublimation of a contaminant and its recondensation deposition of the (Image Omitted) contaminant can occur. Many furnaces operate with a temperature differential of 500oC where the foregoing can take place.

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Redesign of Furnaces Used in Semiconductor Production Lines

A change in the flow of the purging gas mixture used in semiconductor production furnace has been proposed which would prevent outgassing contaminants from depositing on substrates, modules and wafers going through the furnace. The modification would introduce the gas supply into the cooler end zones and exhaust it in the hottest zone, which is opposite from the previous flow pattern. In experiments with a quartz tube simulating the gas flow, it was found that where the temperature range of a furnace allows initial sublimation of a contaminant and its recondensation deposition of the

(Image Omitted)

contaminant can occur. Many furnaces operate with a temperature differential of 500oC where the foregoing can take place. The objective of the proposed change is to develop a flow pattern which will counteract the buildup of high contaminant vapor pressures and which will preclude the deposition of volatiles. In the original design of the furnaces the gas flow 1 (Fig. 1) would enter at the center 2, the hottest region of the furnace, flow over the samples 3 countercurrent to the temperature gradient 4, and exhaust in the cooler end regions 5. The change in the design is to introduce the gas flow 1 (Fig. 2) in the cooler regions 5 and maintain a positive flow to the hotter regions with the gas withdrawal taking place in heated pipes 6 from the areas of maximum temperature. This will achieve the objective state...