Patent ID: 7602197

Claim:
A method for wafer inspection, comprising: inspecting a sample at an inspection rate ‘R’, said sample having a first layer that is at least partly conductive and a second, dielectric layer formed over the first layer said second layer having production contact openings formed therein, said inspecting step comprising; directing a beam of charged particles, said beam having a beam current ‘I b ’ and a spot area ‘A 1 ’, to simultaneously irradiate an area of the sample, said area comprising a quantity ‘n’ of said contact openings, said openings being disposed within an area smaller than A 1 ; measuring a specimen current flowing through the first layer in response to said beam; and providing an indication, in response to the measurement, of whether any hole in quantity ‘n’ is defective, wherein I b is approximately 10 μamps, R is at least 0.2 cm 2 /sec, area A 1 is approximately 25 μm 2 , and an average noise current per contact opening is less than 9 nA.