Methods for fabricating a biochip for detecting or sequencing biomolecules are shown. Such a biochip may for instance include: a base member; a dielectric layer deposited on the base member and having at least two rows of discrete recesses formed thereon; and two or more electrodes sandwiched between the base member and the dielectric layer and running under respective row of discrete recesses, the two or more electrodes separated from each other along lengths thereof by a portion of the dielectric layer; wherein the dielectric layer defines a continuous operation surface above the electrodes and on which the discrete recesses are deposited for detecting or sequencing of biomolecules, when an electric field is applied through the electrodes, a field gradient is created to draw a biomolecule towards a preferred part of the operation surface.