| 摘要 |
PURPOSE:To improve singlecrystallization by crystallizing a non-singlecrystal Si in a well-controlled manner after being subjected to the energy beam irradiation through the use of the crystallizing temperature difference in terms of the impurity density. CONSTITUTION:A non-singlecrystal semiconductor (a polycrystalline Si for instance) 4 is formed via an insulating film (a gate oxide film here) 3 on a substrate 1, and this non-singlecrystal semiconductor 4 is single-crystallized by enlarging its crystal grains by means of the energy beam irradiation. In that case the impurity density in the non-singlecrystal semiconductor region 4 is made partially varied beforehand. For instance, ions are implanted by using an SiO2 film 5 as a mask so that the impurity density at the peripheral parts of the region 4 is made higher than that of the center parts. Because of this, crystallization after the energy beam irradiation starts from the low impurity density parts at the center and proceeds to the higher density parts, thereby enlarging crystal grains. |
