How do you know Vega is TSMC?
Not confirmed to be TSMC, or GloFlo, or Samsung. But the thoughts were they could use something other than GloFlo if they meet their WSA (waffer supply aggrement).
However it was confirmed that AMD can use Samsung 14nm fabrication instead of GloFlo without penalty towards the WSA under certain conditions.
AMD pretty much confirmed it here - http://www.anandtech.com/show/9886/amd-reveals-polaris-gpu-architecture/3
As for RTG’s FinFET manufacturing plans, the fact that RTG only mentions “FinFET” and not a specific FinFET process (e.g. TSMC 16nm) is intentional. The group has confirmed that they will be utilizing both traditional partner TSMC’s 16nm process and AMD fab spin-off (and Samsung licensee) GlobalFoundries’ 14nm process, making this the first time that AMD’s graphics group has used more than a single fab. To be clear here there’s no expectation that RTG will be dual-sourcing – having both fabs produce the same GPU – but rather the implication is that designs will be split between the two fabs. To that end we know that the small Polaris GPU that RTG previewed will be produced by GlobalFoundries on their 14nm process, meanwhile it remains to be seen how the rest of RTG’s Polaris GPUs will be split between the fabs.