Just wanted to share some pictures I snapped today of the three furnaces in action (all at once!) at different temperatures. This was the first time that all three were active at the same time (drawing ~90-100Amps). Look closely and you can see the wafers inside the furnaces.
N Type Diffusion Furnace @ 825°C
P Type Diffusion Furnace @ 925°C
Silicon Dioxide Growth Furnace @ 1075°C