| 摘要 |
PURPOSE:To manufacture a conduction-modulation MOSFET having excellent characteristics at a high yield by a method wherein a high-impurity concentration layer, which brings a base layer into a low-resistance state and is used for preventing a latch-up, is formed at the central part of the base layer in a self-matching manner. CONSTITUTION:Gate electrodes 51 consisting of a poly Si film are formed on the substrate of a structure; wherein an n-type high-resistance layer 3 is formed on a p<+> drain layer 1 through an n<+> buffer layer 2; through a gate insulating film 4. After this, masking materials 6 for covering the intervals between the gate electrodes 51 and first masking materials 52 are formed of a photo resist, for example, and boron, for example, is ion-implanted to form a p<+> layer 7. After a heat treatment is performed and activation and diffusion of the impurity of the p<+> layer 7 are performed, an impurity is doped using the gate electrodes 51 as masks to form a p-type base layer 8 and moreover, a mask is formed on the central part of the p-type base layer 8 and an impurity is doped using this mask and the gate electrodes 51 as masks to form n<+> source layers g. Thereby, the p<+> layer 7 for bringing the p-type base layer 8 into a low-resistance state can be formed at the center of the p-type base layer 8 in a slef-matching manner. |
