| 摘要 |
PROBLEM TO BE SOLVED: To manufacture a semiconductor device through the number of processes smaller than a conventional manufacturing method, wherein a plurality of kinds of field-effect transistors having threshold voltages different from each other are formed. SOLUTION: Nitride films 13 are formed on a p-type semiconductor substrate 11 at portions corresponding to regions 12a-12d for forming a MOFFET. Impurity ions are injected to form channel stoppers 18 with a photoresist pattern 16 serving as a mask which has been formed with the exemption of the portions that correspond to the regions 12a-12d and regions 15 for forming field oxide films 17. The impurity ions are also injected to the regions 12b, 12d through the nitride films 13. After removing the photoresist pattern 16, field oxide films 17 and channel stoppers 18 are formed by thermal oxidation under the presence of the nitride films 13. Subsequently, a photoresist pattern 19 is formed with the exemption of the portions corresponding to the regions 12c, 12d to inject impurity ions therethrough whose concentration is different from that of the first injected one. COPYRIGHT: (C)2004,JPO
|
