Insulated gate field effect transistor structure having a unilateral source extension

摘要

An insulated gate field effect transistor (IGFET) structure (10) includes a source region (14) and a drain region (16) formed in an impurity well (13). A channel region (18) separates the source region (14) from the drain region (16). In one embodiment, a unilateral extension region (17) is formed adjacent the source region (14) only and extends into the channel region (18). The unilateral extension region (17) has a peak dopant concentration at a depth (23) and a lateral distance (24) to provide punchthrough resistance. The IGFET structure (10) is suitable for low (i.e., 0.2-0.3 volts) to medium (0.5-0.6 volts) threshold voltage reduced channel length applications.