| 摘要 |
PURPOSE:To prevent a non-single crystal Si layer from being diffused by phosphorus atoms in PSG film when a heat treatment is performed on the non-single crystal Si layer by a method wherein the density of phosphous atoms in the phosphosilicate glass film located in the vicinity of the interface of non-single crystal semiconductor layer, whereon a heat treatment will be performed, is substantially brought to zero. CONSTITUTION:The first layer of non-single crystal Si film 2 is formed on a substrate through the intermediary of an SiO2 film 1, said non-single crystal Si film 2 is formed into single crystal by performing a laser annealing, and after a semiconductor element has been formed, the substrate is introduced into a reaction tube, and the substrate is heated up by heating the reaction tube. Subsequently, SiH4 gas, O2 gas and POCl3 gas are mixed, the mixed gas is introduced into the reaction tube, and a PSG film is formed by generating a decomposition reaction in the reaction tube. Then, after the supply of POCl2 gas has been stopped at the stage wherein the PSG film is formed in the prescribed thickness, SiH4 gas is introduced on the substrate again, and the second layer of non-single crystal Si layer 4 is formed by the thermal decomposition of the SiH4 gas. Through these procedures, the diffusion of P-atoms into the polycrystalline Si layer from the PSG film located at the lower part can be prevented even when the second layer of non-single crystal Si layer to be laser annealed is formed into single crystal by performing a laser annealing. |
