AIXTRON reactors

In the same manner, PE-CVD of ZnO has been first studied with the goal of improving the crystallinity of c-axis oriented ZnO him growth at low substrate temperature (i.e. between 150 and 300°C) [49,50]. More recently, expanding thermal plasma has been coupled with an LP-CVD chamber in order to deposit natively rough ZnO films [51-53]. Fig. 6.46 shows the expanding thermal plasma aixtron reactor system used at Eindhoven University of Technology to deposit PE-CVD ZnO films. 

Aixtron has manufactured both a cold-wall planetary reactor and a hot-wall planetary reactor for 7 x 2-inch wafer capacity or 5 x 3-inch. The cold-wall reactor has provided very good uniformities and its performance has been described in... 

A more recent and significant, improvement to the horizontal tube is the wrapping of it into circularly symmetric space, resulting in what Aixtron has termed a Planetary Reactor, Figure 4-13b. To counter depletion effects, the wafer platter and wafers are all rotated. Further a graded temperature scheme also is typically used. While this is complex, it has proven effective in production as described below. This system uses a radial flow scheme inside and, thus, provides a controlled depletion in flow direction, producing uniform films over large areas and multiple wafers. 

The photograph in Figure 4-14 shows a Nippon Sanso horizontal reactor in operation at temperature. They use an inverted geometry with full rotation of the susceptor and offer units which handle up to three 100 mm or one 200 mm wafer(s) and offer cassette-to-cassette wafer susceptor transfer. Several other vendors, e.g., Thomas Swan or Aixtron, market horizontal tube systems. CVTis also a well-known horizontal tube system manufacturer and one of the few vendors specializing in HgCdTe systems. 

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