Methods of forming transistors with retrograde wells in CMOS applications and the resulting device structures

A method includes forming a layer of silicon-carbon on an N-active region, performing a common deposition process to form a layer of a first semiconductor material on the layer of silicon-carbon and on the P-active region, masking the N-active region, forming a layer of a second semiconductor material on the first semiconductor material in the P-active region and forming N-type and P-type transistors. A device includes a layer of silicon-carbon positioned on an N-active region, a first layer of a first semiconductor positioned on the layer of silicon-carbon, a second layer of the first semiconductor material positioned on a P-active region, a layer of a second semiconductor material positioned on the second layer of the first semiconductor material, and N-type and P-type transistors.