In the proposed research paper, we are analyzing the conventional Carbon nanotube Field- effect transistor (CNTFET) and its following drawbacks such as high on current, low on-off switching ration, etc. a modified Schottky barrier carbon nanotube field-effect transistor (SB-CNTFET) developed by adjusting its doping concentration of Drain. These newly developed SB-CNTFET structures have benefits of both Schottky barrier and ohmic contact of the lightly doped drain. In the proposed research report, the conclusion drawn from the resource paper shows significant depletion in leakage current as well increment in the on-off current ratio as well as cut-off frequency. The LDD-CNTFET shows commentable immunity boost against the short-channel device effect, which is demonstrated by different analytical experiments.