| 摘要 |
PROBLEM TO BE SOLVED: To make simultaneously formable a high-concentration source and drain region of a high withstanding pressure MOS (metal oxide semiconductor) Tr (transitor) region and a low withstanding pressure MOS Tr region. SOLUTION: A thin first oxide film 2 is formed in the high withstanding pressure MOS Tr region and the low withstanding pressure MOS Tr region, and a LOCOS (local oxidation of silicon) oxide film 4 is formed at ends of both the regions. A second oxide film 8 which is thicker than the first oxide film 2 and thinner than the LOCOS oxide film 4 is formed in the high withstanding pressure MOS Tr region. Thereafter, after gate electrodes 9a, 9b are formed in both the regions, a low-concentration source/drain region is formed in another process. The high-concentration source/drain regions 13a are simultaneously formed at a desired position of the low withstanding pressure MOS Tr region and just under the second oxide film 8 of the high withstanding pressure MOS Tr region. The second oxide film 8 which is thicker than the first oxide film and thinner than the LOCOS oxide film is formed in the high withstanding pressure MOS Tr region, whereby both N+-type source/drain regions of the high withstanding pressure MOS Tr region and the low withstanding pressure MOS Tr region can be formed simultaneously. COPYRIGHT: (C)2004,JPO&NCIPI
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