CMOS structure including differential channel stressing layer compositions

A CMOS structure includes an n-FET device comprising an n-FET channel region and a p-FET device comprising a p-FET channel region. The n-FET channel region includes a first silicon material layer located upon a silicon-germanium alloy material layer. The p-FET channel includes a second silicon material layer located upon a silicon-germanium-carbon alloy material layer. The silicon-germanium alloy material layer induces a desirable tensile strain within the n-FET channel. The silicon-germanium-carbon alloy material layer suppresses an undesirable tensile strain within the p-FET channel region. A silicon-germanium-carbon alloy material from which is comprised the silicon-germanium-carbon alloy material layer may be formed by selectively incorporating carbon into a silicon-germanium alloy material from which is formed the silicon-germanium alloy material layer.