An integrated circuit and a method of making a transistor thereof are provided. In one aspect, the method includes the steps of forming a gate insulating layer on the substrate with a first outwardly tapered sidewall and a second outwardly tapered sidewall. A gate electrode is formed on the gate insulating layer. A first source/drain region and a second source/drain region are formed in the substrate by implanting ions into the substrate, wherein a first portion of the ions passes through the first sidewall and a second portion of the ions passes through the second sidewall. The method provides for incorporation of spacer-like structure into a gate dielectric layer. Conventional spacer fabrication may be eliminated and graded source/drain regions established with a single implant.