FYI, I am a former Hitachi High Tech - Canada employee and I asked one of my colleagues in the US about the Zanker Road, Hitachi HT America office. Hitachi HTA does have a small office there but with no equipment present. Hitachi High Technologies America sells electron beam instruments - wafer inspection equipment, electron microscopes etc.
So make of it what you will, but I do not think that there is an association forming between Hitachi HTA and POET. POET may be using this facility because of its clean room,,,, yes. But IMO there is no association with HTA.
GL.