Techniques for fabricating a semiconductor chip having a curved surface include placing a substantially flat photonic sensor chip on a recessed surface of a mold such that an active region of the photonic sensor chip at least partially covers a concave central region of the mold and an inactive region of the photonic sensor chip at least partially covers a convex peripheral region of the mold. The mold has a radially varying curvature and the recessed surface includes the concave central region and the convex peripheral region concentrically surrounding the concave central region. Pressure may be applied on the photonic sensor chip to press and bend the photonic sensor chip into the mold.