Methods of forming transistor devices with different threshold voltages and the resulting devices

A device, comprising:

• a first transistor device having a first threshold voltage and including a first gate electrode structure positioned in a first gate cavity, said first gate electrode structure including a first gate insulation layer, a first barrier layer formed above a first portion of said first gate insulation layer, a first work function material layer formed above said first barrier layer, a second barrier layer formed above said first work function material layer and a second portion of said first gate insulation layer, and a first conductive material formed above said second barrier layer;
• and
• a second transistor device having a second threshold voltage different than said first threshold voltage and including a second gate electrode structure positioned in a second gate cavity, said second gate electrode structure including a second gate insulation layer, a second work function material layer formed above a first portion of said second gate insulation layer, said second barrier layer formed above said second work function material layer and a second portion of said second gate insulation layer, and a second conductive material formed above said second barrier layer, wherein an uppermost height of each of said first and second work function material layers is less than an uppermost height of said first and second conductive materials, respectively, and said first gate electrode structure has a first work function higher than a second work function of said second gate electrode structure.