| 摘要 |
<p>An integrated circuit containing high voltage PMOS and/or NMOS devices as well as low voltage PMOS and/or NMOS devices and a simple low cost method for making same that is adaptable to many types of semiconductor processes; furthermore, the breakdown voltage of the high voltage devices is easily adjusted so that the value of Ron can be optimized. High voltage MOS devices (6,7) are formed on substrate (10) using essentially the same process steps as are used to form low voltage MOS devices (8,9). Low values of Ron are obtained by selecting impurity concentration levels for HV drift region n-tank (21) and for HV drift region p-tank (41) so that the depletion region distance D1 bounded by equipotential lines (301a,301j) and the depletion region distance D1a bounded by equipotential lines (401a,401h) are smaller than the physical size D2 and D2a of drift regions (41,21), respectively, thereby forming an extended drain structure. <IMAGE></p> |
