We examine correlations of the Möbius function over Fq [t] with linear or quadratic phases, that is, averages of the formfor an additive character χ over Fq and a polynomial Q ∈ Fq[x0, . . . , xn−1] of degree at most 2 in the coefficients x0, . . . , xn−1 of f = i 0 if Q is linear and O q −n c for some absolute constant c > 0 if Q is quadratic.The latter bound may be reduced to O(q −c ′ n ) for some c ′ > 0 when Q(f ) is a linear form in the coefficients of f 2 , that is, a Hankel quadratic form, whereas for general quadratic forms, it relies on a bilinear version of the additive-combinatorial Bogolyubov theorem.