Manufacturing method for solar cell, solar cell, and solar cell manufacturing apparatus

Abstract

A method includes: forming an n-type diffusion layer as a second-conductivity-type semiconductor layer on a first-conductivity-type crystalline semiconductor substrate; and forming an anti-reflective film by a CVD method to extend from a light receiving surface side to a side surface of the semiconductor substrate, by placing the semiconductor substrate on a mount in a film forming chamber with a back surface brought into contact with the mount, evacuating and decompressing the film forming chamber, and supplying source gas into the film forming chamber. In the film formation, a tray has a through hole, and the anti-reflective film is formed on the surface of the semiconductor substrate excluding the contact surface by bringing the semiconductor substrate into close contact with the contact surface by causing the through hole to have a negative pressure relative to the pressure in the film forming chamber by the evacuation.

1 . A solar cell manufacturing apparatus that is a CVD apparatus comprising:
 a film forming chamber;   a first electrode that is disposed in the film forming chamber;   a second electrode that faces the first electrode and also serves as a substrate mount on which a semiconductor substrate is mounted;   a gas supply portion to supply a source gas into the film forming chamber; and   an evacuation portion to evacuate the film forming chamber to generate a negative pressure in the film forming chamber,   wherein the substrate mount has a through hole that has an opening in a first contact surface of the substrate mount contacting a second contact surface of the semiconductor substrate, passes through the substrate mount, and opens into the film forming chamber at another end, and   wherein the through hole is the only through hole of the substrate mount in the first contact surface of the substrate mount, and the opening is the only opening of the through hole in the first contact surface of the substrate mount.   
     
     
         2 . The solar cell manufacturing apparatus according to  claim 1 , wherein the substrate mount has a groove in addition to the through hole. 
     
     
         3 . The solar cell manufacturing apparatus according to  claim 2 , wherein
 the opening of the through hole is at a center of the first contact surface, and   the groove is a double H shaped groove that encloses the through hole with a center of the through hole as a center, and includes four orthogonal grooves with four ends located at both ends of two of the four orthogonal grooves protruding from the semiconductor substrate.   
     
     
         4 . The solar cell manufacturing apparatus according to  claim 2 , wherein
 the opening of the through hole is at a center of the first contact surface with the semiconductor substrate, and   the groove is a hash mark (#) groove that encloses the through hole with a center of the through hole as a center, and includes four orthogonal grooves with eight ends of the four orthogonal grooves protruding from the semiconductor substrate.   
     
     
         5 . The solar cell manufacturing apparatus according to  claim 1 , wherein the through hole is a tapered hole formed to have a larger cross-sectional area as the hole is farther away from the opening. 
     
     
         6 . The solar cell manufacturing apparatus according to  claim 1 , wherein the substrate mount includes a recessed groove that is formed in a region corresponding to the periphery of the semiconductor substrate, and an elastic body that is fitted into the recessed groove. 
     
     
         7 . The solar cell manufacturing apparatus according to  claim 1 , wherein the through hole includes:
 a first hole provided on the first contact surface of the substrate mount and having a first opening, the first opening being the opening of the through hole in the first contact surface of the substrate mount; and   a second hole provided on a back surface of the substrate mount and having a second opening, wherein   the first hole is communicated with the second hole, and a cross-sectional area of the first hole is larger than a cross-sectional area of the second hole.