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 s, 45 s), D = mask dimension (small, large), and E = etch time (14.5 min, 15.5 min). The unreplicated 2° design shown below was run. (1) = 7 8 e = 8 de = %3D a = 9 ad 10 de = 12 ade 10 b = 34 bd = 32 be = 35 bde = 30 ab = 55 abd = 50 abe = 52 abde = 53 %3D c = 16 cd = 18 се — 15 cde = 15 ac = 20 аcd 21 ace = 22 acde = 20 bc = 40 bcd = 44 bce = 45 bcde = 41 abc = 60 abcd = 61 abce = 65 abcde = 63 (a) Construct a normal probability plot of the effect estimates. Which effects appear to be large? (b) Conduct an analysis of variance to confirm your findings for part (a). Hint: Conduct analysis of variance with the large effects found in (a), and draw conclusion. (c) Write down the fitted regression model relating yield to the significant process variables. (d) Interpret any significant interactions. Hint: Construct interaction plot. (e) What are your recommendations regarding process operating conditions?