| 摘要 |
PURPOSE:To improve spectroscopic sensitivity on the side of short wavelength, to prevent decrease in lifetime of a substrate in heat treatment, to decrease the recombination speed at the surface of a light receiving plane and to improve throughput, by implanting ions through an oxide film layer located on the surface of a substrate, forming a junction deeply at the electrode part of the light receiving plane other than a bypass, forming the junction shallowly at a light receiving part, and utilizing the oxide film as a protecting film in heat treatment. CONSTITUTION:In ion implantation, the amount of implantation in a substrate can be controlled by changing the thickness of an oxide film on the surface of the substrate. In consideration of this fact, ions are implanted into a part other than an oxide film 2 where finger electrode parts 6 are provided on a surface electrode part of a light receiving plane. A deep junction having a low sheet resistance is formed at this part. Meanwhile, the ions are implanted through the oxide film 2 into a part which is to become a light-receiving part, and a shallow junction is formed. The oxide film 2 is made shallow at a part where the light-receiving part and a bus bar 7a are formed. Thus a surface recombination speed is further decreased. The oxide film 2 is also utilized as a protecting film for preventing the decrease in lifetime in heat treatment of the oxide film 2. The film 2 is used as a passivation film for decreasing the surface recombination speed of the light receiving plane. The throughput is increased, and a highly efficient solar cell is obtained in this way. |
