Consider the problem in Exercise 14-19. Suppose that only half of the 32 runs could be made.

(a) Choose the half that you think should be run.

(b) Write out the alias relationships for your design.

(c) Estimate the factor effects.

(d) Plot the effect estimates on normal probability paper and interpret the results.

(e) Set up an analysis of variance for the factors identified as potentially interesting from the normal probability plot in part (d).

(f) Analyze the residuals from the model.

(g) Provide a practical interpretation of the results.

Exercise 14-19

An experiment was run in a semiconductor fabrication plant in an effort to increase yield. Five factors, each at two levels, were studied. The factors (and levels) were A = aperture setting (small, large), B = exposure time (20% below nominal, 20% above nominal), C = development time (30 and 45 seconds), D = mask dimension (small, large), and E = etch time (14.5 and 15.5 minutes). The following unreplicated 25 design was run:

(1) = 12 = 35 = 52 = 15 = 22 45 = 65 9. a ae = 34 = 55 = 16 = 20 = 40 = 60 be abe ab ce ac ace bc abc bce abce = 6 de = 10 = 10 ad ade bde = 32 abd = 50 cd = 30 abde = 53 cde bd = 15 acde = 20 bcde = 41 abcde = 63 18 acd = 21 bcd = 44 abcd = 61