An n-channel device (10) and a p-channel device (11) are formed from a single epitaxial silicon layer (60,61). During the deposition of the single epitaxial silicon layer (60,61), dopants are added to the epitaxial reaction chamber and subsequently changed to define a drain region (24,33), a channel region (27,34), and a source region (30,35). The dopant concentration is modified during the formation of the channel region (27,34) to create a doping profile (50). The doping profile (50) has a first profile (51) that is constant and a second profile (52) that changes.