In semiconductor wafer fabrication different tests and measurements are done to characterize processes, such as electrical measurements. Electrical characteristics such as resistivity and therefore the specific resistance need to be considered.
A good overview on the correlation between both can be found here:
http://hyperphysics.phy-astr.gsu.edu/hbase/electric/resis.html
More info:
Sheet Resistance and the Calculation of Resistivity or Thickness Relative to Semiconductor Applications
