Electronic structure comprising high and low voltage transistors, and a corresponding fabrication method

Abstract

A structure of electronic devices integrated in a semiconductor substrate with a first type of conductivity comprising at least a first HV transistor and at least a second LV transistor, each having a corresponding gate region. Said first HV transistor has lightly doped drain and source regions with a second type of conductivity, and said second LV transistor has respective drain and source regions with the second type of conductivity, each including a lightly doped portion adjacent to the respective gate region and a second portion which is more heavily doped and comprises a silicide layer.

We claim:  
     
         1 . A structure of electronic devices integrated in a semiconductor substrate having a first type of conductivity, the structure comprising a high voltage transistor and a low voltage transistor, each having a corresponding gate region, wherein said high voltage transistor has a drain region lightly doped with a second type of conductivity, and said low voltage transistor has respective drain and source regions with the second type of conductivity, each including a lightly doped portion adjacent to the gate region of said low voltage transistor and a second portion which is more heavily doped, wherein said second portion comprises a silicide layer.  
     
     
         2 . A structure according to    claim 1    wherein said gate region of the low voltage transistor comprises a silicide layer.  
     
     
         3 . A structure according to    claim 1    wherein said gate region of the high voltage transistor comprises a silicide layer.  
     
     
         4 . A structure according to    claim 1    wherein a source region of the high voltage transistor is lightly doped.  
     
     
         5 . A structure according    claim 1    wherein the high voltage transistor includes a source region, the drain and source regions of the high voltage transistor each comprising a contact region that is more heavily doped than a remainder of said drain and source regions of the high voltage transistor.  
     
     
         6 . A structure according to    claim 1    wherein said contact regions of the high voltage transistor comprise a silicide layer.  
     
     
         7 . A structure according to    claim 1    wherein the gate region of the high voltage transistor includes an oxide layer that is thicker than an oxide layer of the gate region of the low voltage transistor.  
     
     
         8 . An electronic memory device integrated in the semiconductor substrate and comprising the structure recited in    claim 1   .  
     
     
         9 . A structure of electronic devices integrated in a semiconductor substrate having a first type of conductivity, the structure comprising: 
 a high voltage transistor having gate, drain, and source regions, the drain being lightly doped with a second type of conductivity; and    a low voltage transistor having gate, drain, and source regions, the drain and source regions of the low voltage transistor each having the second type of conductivity and each including a lightly doped portion adjacent to the gate region of the low voltage transistor and a second portion that is more heavily doped, wherein the gate, drain, and source regions of the low voltage transistor are each covered by a silicide layer.