| abstract |
A semiconductor device includes a substrate including a first region and a second region, a first transistor and a second transistor formed in the first region and second region, respectively, wherein the first transistor includes a thick gate insulating layer and a thin buffer insulating layer formed in the substrate, a first gate electrode formed on the thick gate insulating layer, a first spacer formed on the thin buffer insulating layer, and a source region and a drain region formed in the substrate. |