New sources may be cleaned and must be properly aged before they are used in testing or production. Refer to and Product Bulletin Aging for instructions. In this process, the sources should be aged at the recommended deposition temperature for at least 16 hours but no longer than 24 hours.

Deposition Cycle

Caution: Any time BoronPlus sources are exposed to temperatures above 600oC, silicon wafers should be placed between each pair of sources and at each end of the load.

Special Instructions

SI 1
The gas flow rate recommended is based on experience with a variety of different systems. Some customers have found that increasing the gas flow rate during insertion and withdrawal will further decrease the chances of moisture backstreaming from the mouth of the furnace. This technique is particularly useful if only an end plate is used to cover the cap of the furnace, or if the end cap is loose fitting.

SI 2
Initially, the indicated percentage of oxygen should be blended into the carrier gas for the initial series of tests. Eventually, the oxygen concentration that produces acceptable results for your process should be selected. Normally, this will be between 0.5% and 5%. The PhosPlus sources are not affected by oxygen.

SI 3
Variations in the humidity level of plant air could cause variations in sheet resistivity. To reduce the effects of moisture, the following steps are recommended:

• After predeposition, cool the silicon and sources in dry nitrogen.
• When not in use, always store the sources in dry nitrogen at an elevated temperature.

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