material 303 d provides an electrical isolation to the sidewalls of the empty part 302 d u2032 and therefore avoids forming a current leakage path or the failure of the p n junction in the epitaxial stack 302 in addition when an electrode passes or is located on the empty part 302 d u2032 the dielectric material 303 d provides an electrical isolation between the electrode and the junction to avoids a shortage as shown in fig3 k an anti reflective layer 304 the first electrode 305 and the second electrode 306 are subsequently formed the main portion of the anti reflective layer 304 is formed on the epitaxial stack 302 while a portion of the anti reflective layer 304 is formed on the dielectric material 303 d to fill the concave part caused by the empty part 302 d u2032 in fig3 e with the dielectric material 303 d formed thereon the first electrode 305 is formed in the anti reflective layer 304 and on the epitaxial stack 302 the second electrode 306 is formed on the surface of substrate 301 opposite to the surface on which the epitaxial stack 302 is disposed and in fig3 l as mentioned above the cutting lines are formed around a solar cell chip and the substrate 301 is cut along the cutting lines as indicated by the line ll u2032 to form the solar cell chips it is noted that the process flow shown in this embodiment may be adjusted by the person of the skill in the art for example though the cutting line pattern i e the mask used exposing is performed before the detecting step in this embodiment it is apparent that the mask.