| 摘要 |
PURPOSE:To simplify the process while enhancing the quality by a method wherein the part immediately below a collector electrode is flattened as well the second junction is simultaneously formed on this part by novel and efficient processes. CONSTITUTION:The (100) surface of a P type Si substrate 1 is roughened by NaOH solution and thermal-diffused in POCl2 gas to form an n<+> layer on the surface. The substrate 1 with the first junction 5 held in a collector electrode formation region in a PH3 gas chamber 11 is irradiated with short wave length laser beams 10 in specified wavelength and energy at proper radiant through the window 12 of the gas chamber 11. The whole substrate is not heated at all but very shallow layer only is melted down. The roughened surface is flattened by the melting down process to cause the second junction 4 comprising an n++layer. An Al-Si alloy 7 and an Al electrode 6 are simultaneously formed on the rear surface of the substrate 1 while a TiO2 reflection preventive film 8 and a surface electrode 9 are formed on the surface to complete the processes. In such a constitution, the processes can be simplified notably to manufacture the title solar cell in high efficiency and high quality. |
