Methods to produce asymmetric MOSFET devices

Abstract

Metal Oxide Semiconductor Field Effect Transistors (MOSFET) are disclosed. One MOSFET includes, a substrate having a well of a first conductivity type. The MOSFET also includes source and drain regions, of a second conductivity type, formed in the well arranged apart from each other. Moreover, the MOSFET includes a first region, of a second conductivity type, formed in the well near the drain region. The first region has a low doping. Furthermore, the MOSFET includes a second region of a second conductivity type, formed near the source region. The second region has a doping substantially higher than the doping of the first region. A second MOSFET includes a substrate having a well of a first conductivity type and source and drain regions, of a second conductivity type, formed in the well apart from each other. Moreover, the MOSFET includes a drain extension region of the second conductivity type, formed in the well near the drain region. Furthermore, the MOSFET includes a source extension region, of the second conductivity type, formed in the well near the source region. The source extension region is doped more heavily than the drain extension region. The source extension region extends deeper in the well than the drain extension region.

Dependencies are inferred from the claim text.