The VLSI placement problem is to place the objects into fixed die such that there are no overlaps among the objects and some cost metric such as wire length and routability is optimized. For this purpose A new routing method is used - called , A Deep sub-wavelength lithography, (using the 193nm lithography to print 45nm, 32nm, and possibly 22nm integrated circuits), is one of the most fundamental limitations for the continuous VLSI scaling,. Lithography printability is strongly layout dependent, thus routing plays an important role in addressing the overall circuit manufacturability and product yield since it is the last major physical design step before tape out. This paper will discuss some recent advancement of lithography friendly routing from post-routing hotspot fixing (construct by- correction) to during-routing hotspot avoidance (correct-by construction) guided by various lithography metrics.