Semiconductor devices including an active fin and a drift region

A semiconductor device may include an active fin, an element isolation film on a lower portion of the active fin and a gate structure crossing over the active fin. The gate structure may include first and second sides. The device may also include a source region and a drift region adjacent the first and second sides of the gate structure, respectively. The drift region may have a first impurity concentration. The device may further include a drain region that is in the drift region and may have a second impurity concentration higher than the first impurity concentration, a first trench that is in the drift region and may have a depth less than a height of the active fin, and an upper embedded insulating layer in the first trench. The gate structure may overlap a portion of the drift region and a portion of the first trench.