NOVELTY - An N-type silicon heterojunction battery comprises an N-type silicon substrate having a front surface covered with aluminum oxide film which is covered with silicon nitride (SiN) film, and a back surface formed with intrinsic amorphous silicon and P-type amorphous silicon by deposition. The intrinsic amorphous silicon and P-type amorphous silicon are provided with grooves. The bottom part of grooves has N-type heavily doped area. A negative electrode is arranged in the groove. A positive electrode is provided on the back surface of P-type amorphous silicon.    USE - N-type silicon heterojunction battery.    ADVANTAGE - The battery has IBC structure and can fully utilize solar spectrum, thus, the short-circuit current density of battery is improved to a large extent. No P-type heavily doped area is formed, thus, stability of solar battery is improved.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for fabrication of N-type silicon heterojunction battery with integrated battery cabinet (IBC) structure by:    (A) selecting N-type silicon substrate with resistivity of 0.3-6 ohm cm and service life of more than 300 mu s;    (B) texturing substrate surface and chemically cleaning;    (C) depositing intrinsic amorphous silicon and P-type amorphous silicon on back surface of substrate by growing intrinsic amorphous silicon with length of 10-20 nm from mixed gas comprising silane and hydrogen at ratio of 1:10 to 1:1 at 180-250 degrees C; and growing P-type amorphous silicon with length of 10-25 nm from mixture of silane, hydrogen and trimethylboron (TMB) at 180-250 degrees C, in which the ratio of silane to hydrogen is 1:10 to 1:200 and the ratio of silane to TMB is 1:1 to 1:4;    (D) forming N-type heavily doped area by forming slot with width of 100-300 nm on back surface of substrate via UV laser of 355 nm and removing intrinsic amorphous silicon and P-type amorphous silicon, or printing corrosive slurry on position to be slit, removing intrinsic amorphous silicon and P-type amorphous silicon, and washing slurry with pure water; coating a layer of 5-10% phosphoric acid on surface of substrate; and doping via UV laser of 355 nm;    (E) forming aluminum oxide film on front surface of substrate by atomic layer deposition of aluminum oxide film with thickness of 30 nm from mixture of trimethylaluminum and water or ozone, or mixture of aluminum chloride and water at 400 degrees C, in which the aluminum oxide film carries negative charge of 1x 1012-3x 1013 cm2;    (F) forming SiN film on front surface of aluminum oxide film by plasma chemical vapor deposition of SiN film with thickness of 73-79 nm from tetraethoxysilane or mixture of silane and nitrous oxide;    (G) forming positive and negative electrodes; and    (H) annealing in atmosphere at 150-220 degrees C for 30-60 minutes.