Let $\phi:X\to Y$ be an etaleétale morphism of noetherian schemeNoetherian schemes. Does $\phi$ have to be quasi-affine? In other wardswords, if $Y$ is affine does it mean that $X$ is quasi-affine?
It will follow from the fact that quasi-finitfinite morphisms are quasi-affine, but I do not know whether this is true.