| 摘要 |
A method for forming an epitaxial layer upon a semiconductor substrate by vapor phase epitaxy is carried out within a quasi-open system having a controllably pressurized vertically orientated reaction chamber containing a charge of source material at a lower closed end. The chamber is heated at the lower end within a furnace such that the source material is vaporized. The substrate is introduced through an upper transfer chamber, passing through a gate valve so that it may be positioned by a moveable rod in a lower region of the chamber within the vapor given off by the source material. The source material vapor is deposited on the substrate, forming an epitaxial layer thereon. A cooling coil cools a portion of the chamber above the heated portion, thereby condensing the source vapor which may enter the cooled portion, such that the condensed vapor will remain in the lower, heated portion of the chamber. The transfer chamber and gate valve allow for maintaining the pressure within the chamber while the substrate is entered therein and during positioning. By varying the pressure within the chamber the composition of the vapor may be controlled and, hence, the composition of the epitaxial layer.
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