| 摘要 |
PURPOSE:To provide a remarkably large and lateral diffused-region on a substrate surface under a thick insulating film, by forming a impurity diffused region on the surface layer of a semiconductor substrate, through a polycrystalline alloy layer having a rapid impurity diffusing rate. CONSTITUTION:After an SiO2 film 101 is coated on a P type Si substrate 100, an opening is bored and an Mo film 102 is deposited on the entire face. Next, Si ions are implanted to form a mixing layer of Mo and Si. The substrate is then heat-treated to produce silicide reaction only in the opening and to leave the Mo film 102 on the film 101 with a non-reacted state. After the non-reacted Mo film 102 is removed using H2O2 etching liquid, the film 101 is removed with HF aqueous solution and an Mo silicide layer 103 is formed on the substrate 100 surface. Thereafter, the entire surface is coated with an SiO2 film 104 which is then heat-treated to make dense and through which an opening is bored with being positioned at the central surface portion of the layer 103. Next, after an SiO2 film 106 is coated on the entire face including the exposed face 105 of the layer 103, an N type diffused region 107 being expanded laterally under the layer 103 can be provided owing to being diffused in POCl3 contained gas. |
