The present disclosure relates to a transistor device having a channel region comprising a sandwich film stack with a plurality of different layers that improve device performance, and an associated apparatus. In some embodiments, the transistor device has a source region and a drain region disposed within a semiconductor substrate. A sandwich film stack is laterally positioned between the source region and the drain region. The sandwich film stack has a lower layer, a middle layer of a carbon doped semiconductor material disposed over the lower layer, and an upper layer disposed over the middle layer. A gate structure is disposed over the sandwich film stack. The gate structure is configured to control a flow of charge carriers in a channel region located between the source region and the drain region.