Hi,
I am a non-eu citizen and i am about to start my PhD at ETH Zurich which they offered me a research assistant position. I have already applied for the work permit(B-permit) and other formalities and i have sent the work permit application to the the immigration office of Zürich canton . I was wondering if i still need to apply for visa separately or the immigration office will issue the visa for me and how long will roughly take to issue the visa?

Cheers.