Semiconductor device and its manufacturing method

Abstract

The objective of this invention is to provide a semiconductor device and its manufacturing method with which the offset can be kept fixed even in high breakdown voltage MOS transistors, and that can accommodate high voltages for high breakdown voltage MOS transistors and miniaturization of MOS transistors for low voltage drive. Its constitution provides for inner side wall insulating films 14 and 24 and outer side wall insulating films 16 and 26 formed at both sides of the gate electrodes 12 and 22 in both high breakdown voltage transistor TR 2 and transistor TR 1 for low voltage drive, and heavily doped region 27 is formed in breakdown voltage transistor TR 2 using both inner side wall insulating film 24 and outer side wall insulating film 26 as masks so that offset d 2 is controlled by the combined widths of the two side wall insulating films. In transistor TR 1 for low voltage drive, heavily doped region 15 is formed using only inner side wall insulating film 14 as the mask, and offset d 1 is controlled.

1 . An integrated circuit, comprising: 
 a first transistor having a first breakdown voltage; and    a second transistor having a second breakdown voltage greater than said first breakdown voltage;    wherein: 
 said first and second transistors each comprise a gate electrode, a first sidewall spacer located adjacent said gate electrode, a second sidewall spacer located adjacent said first sidewall spacer, and heavily doped source and drain regions, wherein said heavily dopes source and drain regions of the first transistor extend further under said first and second sidewall spacers than the heavily doped source and drain regions of the second transistor.  
   
   
   
       2 . (canceled)