| 摘要 |
PURPOSE:To eliminate a back channel of a thin film MOS transistor by diffusing an impurity of a region which contains second conductivity type impurity by thermally diffusing in a thin semiconductor film during the step of forming an MOS transistor to form a second conductivity type diffused region, thereby introducing the impurity without using an ion implanting method. CONSTITUTION:After an SiO2 film 10 is formed on a glass substrate 9, B and P are introduced to form a region 11 which contains a P-type impurity and a region 12 which contains an n-type impurity. After a thin silicon film is then deposited on the film 10, its crystallinity is improved by a means for recrystallizing by laser annealing, n-type and p-type MOS transistors 20, 30 separated by dielectric are formed. when forming them, the B and the P are diffused from the region 11 and the region 12 into a thin silicon film in the thermal step of oxidizing and diffusing to form a p<+> type diffused region 15 and an n<+> type diffused region 16. In a CMOS transistor manufactured in this manner, a p<+> type diffused region 15 and an n<+> type diffused region 16 are easily formed to prevent a back channel. |
