An apparatus is provided which comprises: a source and a drain with a channel region therebetween, the channel region comprising a semiconductor material, and a gate dielectric layer over at least a portion of the channel region, wherein the gate dielectric layer comprises a first thickness proximate to the source and a second thickness proximate to the drain, wherein the second thickness is greater than the first thickness, and wherein at least a portion of the gate dielectric layer comprises a linearly varying thickness over the channel region. Other embodiments are also disclosed and claimed.