Asm International N.v.

Tom A Van Kesteren

Jan Zinger

A single substrate reactor system for processing batches of product substrates one at a time is provided with at least one dummy substrate. In the time after one batch of product substrates is processed and before another batch of product substrates is ready for processing, the dummy substrate is used as a substitute for the thermal load presented by a product substrate. The dummy substrate is loaded into and unloaded from the reactor in the same manner as a batch of product substrates. Advantageously, the thermal load presented by the dummy substrate maintains the thermal equilibrium established during the processing of a batch of product substrates, thereby eliminating the need for and time required to re-establish this equilibrium at the beginning of processing the next batch of substrates.

Dummy substrate for thermal reactor

A floating substrate reactor allows heat treatment of a series of semiconductor substrates, one by one. The heat treatment occurs while flowing gas suspends a substrate between two heated surfaces of the reactor. The two heated surfaces each have multiple heating zones. The heating zones are heated to desired temperature(s) and a substrate is then loaded into the reactor for heat treatment. Upon loading, the relatively cold substrate absorbs heat and cools the process chamber. A heat spike, which can be varied, is applied to the heating zones to heat the reactor to the desired temperature again. The substrate, however, is unloaded from the reactor before the temperatures of the heating zones have reached the desired temperature. After the heating zones have reached the desired temperature, the next substrate in the series of substrates is loaded into the reactor for heat treatment. The heating rate of each heating zone is independently controlled by two nested control loops in a cascade temperature control configuration, permitting differences in the heating rates of the heating zone to be accounted for, thus allowing a uniform temperature or predetermined gradient to be established across all the heating zones. The intensity of the heat spike is recalculated after the introduction of each substrate, using the heating behavior of the previous heat spike as a calculation input, to more accurately heat the heating zones to the desired temperature. The variability of the heat spike intensity from substrate to substrate also allows the throughput of the heat treatment apparatus to be varied.

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Bilthoven, Netherlands

Tom A Van Kesteren