A method of manufacturing a power switching transistor for a fluid ejection device includes forming a diffused drain region and a diffused source region separated by a channel region. The diffused drain region and the diffused source region are doped with a first dopant. A first portion of the diffused drain region is doped with a second dopant, such that the first portion of the diffused drain region has a greater impurity concentration than at least a second portion of the diffused drain region and has a greater impurity concentration than the diffused source region.
