Rapro Technology

Fred Wong

Yen-Hui Ku

Ahmad Kermani

Mike F Robertson

A reaction chamber for a controlled reaction on a reaction surface of a sample provides for controlled distribution of radiant energy over the reaction surface to offset radiant heat loss of the sample, and establishes uniform distribution of reactant flow on the sample. A lamp housing supplies radiant energy over the sample, which absorbs at least a component of the radiant energy. A support member which supports the sample within the reaction chamber is formed of a material which is essentially transparent to the radiant energy so that it does not behave as a susceptor. An array of lamps, is mounted with the reaction chamber so that direct radiant energy is transmitted through a window to the reaction surface of the sample. A reflecting surface on the housing includes a lamp seat for each lamp in the array with an individually specified position, curvature and tilt with respect to the reaction surface. A source of reactant gas is coupled through a gas port to the reaction chamber between the window and the reaction surface. A reactant distribution plate is mounted between the gas port and the reaction surface, and causes distributed flow of reactant gas over the reaction surface. The distribution plate includes a plurality of perforations having a pattern which determines the distribution of reactant gas flow.

Reaction chamber with controlled radiant energy heating and distributed

A method for inducing a reaction in a reaction chamber of a reactive carrier having a first specific heat, on a reaction surface of a substrate. The method comprises the steps of supporting the substrate in the reaction chamber. Next, the substrate is heated to a reaction temperature, so that the reaction surface has an essentially balanced temperature distribution. The reactive carrier is mixed with an inert gas having a second specific heat to form a reaction mixture, wherein the second specific heat is lower than the first specific heat. Finally, the reaction mixture is supplied into the chamber so that it flows over the surface of the substrate. Because the inert gas has a lower specific heat than the carrier, the overall specific heat of the reaction mixture is reduced. With a lower specific heat, less heat is transferred from the wafer into the reaction mixture. This reduces convective heat loss and thermal gradients in the substrate. The technique is particularly applicable to rapid thermal processing of semiconductor wafers for epitaxial growth of silicon. According to this aspect, hydrogen is the reactive carrier, mixed with a chlorinated silicon source. The inert gas may be argon.

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Fremont, CA, United States of America

Fred Wong