Crystallinity forms the third corner of epi trilemma. The quantification of crystallinity has been difficult since this can be very subjective. However, we obtain the crystallinity by simply looking at the percentage of epitaxial structure that is in direct correlation with the Silicon atomic template. The crystallinity of an epitaxial plug is directly related to how well it is able to handle the lattice strain. Typically, if you have a highly doped epitaxial structure, the tensile strain will be high. This high tensile strain will increase the probability of lattice bond breakages . These breakages in lattice bonds would mean the epitaxial plug would lose its monocrystallinity and start inducing defects, which can induce traps and affect device functionality . Therefore, low doping would improve the crystallinity and high doping is detrimental to crystallinity.