The fundamental physics behind the development of epitaxial process is the trilemma, which dictates that we must lose on one of the three factors (height, dopant concentration and crystallinity). To highlight this, we have created five different epi recipes (R1-R5). Each recipe is designed in a process space in the epi trilemma. A bigger CD results in higher epi height. This also correlates with the basic mechanism of epitaxy growth which tells us that higher CD would result in higher open area silicon, thereby leading to higher dep rate. The relationship between incoming CD and the epi height can be approximated as a linear relation to the first order. The linear fits for each recipe shows that this first order linear relationship works well for our case. In order to understand, the epi trilemma, in regard to epi height, we therefore normalize the epi height with respect to a constant incoming CD. In this case, we choose the normalized epi height with respect to a constant incoming CD of 12 nm. This normalization is done by a simple equation: Normalized Epi height = [Actual epi height (nm) x 12] / Actual CD (nm). This allows us to fairly compare the epi height across multiple wafers with incoming CD variation.