Patent ID: 8178932
Filing Date: 2012-05-15
Classification: H01L

Abstract:
1. A semiconductor device, comprising: a semiconductor substrate; a first transistor formed over the semiconductor substrate, the first transistor having a threshold voltage (Vth) adjusted to a first Vth by a first dopant, the first dopant having a first peak of concentration at a first depth; and a second transistor formed over the semiconductor substrate, the second transistor having the same channel-type as that of the first transistor and having a Vth adjusted to a second Vth by a second dopant, the second dopant having a second peak of concentration at a second depth substantially equal to the first depth and having a concentration higher than that of the first dopant; wherein the first dopant and the second dopant are dopants comprising the same constituent element, the first transistor has a first gate insulating film formed over the semiconductor substrate and a first gate electrode formed over the first gate insulating film, and the second transistor has a second gate insulating film formed over the semiconductor substrate thinner than the first gate insulating film and a second gate electrode formed over the second gate insulating film having a gate length shorter than that of the first gate electrode.