Design and construction of an Ultra High Vacuum Chemical Vapor Deposition for group IV material growth

Silicon is the dominant material used in microelectronics, upon which the semiconductor industry has built cutting edge processors and solid state memory at a pace that doubles the amount of transistors on a chip every two years. A problem with electronics that are based on silicon is the preclusion it has at efficiently interacting with light. Semiconductor lasers and light emitting diodes are made with more expensive alloys from group III-V and II-VI of the periodic table which provide efficient light interactions via direct band gap transitions. However, due to the atomic lattice spacing differences between these current photonic alloys and silicon, the ultimate goal of combining photonics with electronics has yet to be achieved. New materials based on all group IV elements; silicon, germanium, and tin have recently been of interest as the gateway to silicon phonics.;An Ultra High Vacuum Chemical Vapor Deposition (UHV-CVD) chamber was constructed and tested for structural operability so that growth and device experiments with group IV based alloys could be conducted. It was found that this reaction chamber has a total internal volume of 69.2+/-0.1 liters and can consistently achieve pressures below 10-9 Torr, with highest vacuum obtained so far 5.3+/-0.3x10-10 Torr. The leak rate of the reaction chamber and load chamber was found to be 2.3+/-0.5x10-9 torrxliter/second and 1.32x10 -8+/-0.06 torrxliter/second respectively. Plasma enhancement capability through the use of argon plasma showed that an increase in RF power resulted in an increase of plasma intensity. Argon plasma experiments also showed that depositions using plasma enhancement is independent of gas flow indicating a favorable deposition environment. Leak rate experiments, repeatable base pressure, and plasma enhancement demonstrated that a system capable of UHV-CVD was constructed.