Semiconductor wafers are produced by a process that is subje

Semiconductor wafers are produced by a process that is subject to two types of flaws, labeled A and B. The average number of flaws of each type in 1 m^2 of wafer is as follows: The number of flaws X of each type on a wafer of given size follows a Poisson distribution, defined where X depends on the type of flaw (A or B) and the size of the wafer. The A and B flaws are independent. Write expressions for the following probabilities. The following are for a 1m^2 wafer. Fewer than 2 type-A flaws: p(0, 4) + p(1, 4) The following are for a 10 m^2 wafer.

Solution

b) P(0,4)

c) P(0,4) + P(0,3)

d) P(3,3) + P(4,3) + P(5,3) + P(6,3)

e) 1 - { P(0,4) + P(1,4) + P(2,4) + P(3,4) }

f) P(0,7) + P(1,7) + P(2,7)

g) Mean = 7

h) Varance = 7

i) P(0,40)

j) P(1,40) * P(1,30)

k) Mean = 70

l) Variance = 70