Stat 4706 HW 5 Solutions
Total Points Possible: 23
1) In “Orthogonal Design for Process Optimization and Its Application to Plasma Etching”
(Solid State Technology, May 1987), Yin and Jillie describe an experiment to determine the
effect of C2F6 on the uniformity of the etch on a silicon wafer used in integrated circuit
manufacturing. Three flow rates are used in the experiments, and the resulting uniformity for six
replicates is shown below.
Observations
Flow Rate 1 2 3 4 5 6
125 2.7 4.6 2.6 3.0 3.2 3.8
160 4.9 4.6 5.0 4.2 3.6 4.2
200 4.6 3.4 2.9 3.5 4.1 5.1
a) Using Minitab, generate a boxplot for each of the flow rates (either 3 separate graphs or
all 3 boxplots on 1 graph like in the notes).
flowrate
Y
200
160
125
5.04.54.03.53.02.5
Boxplot of Y vs f lowrate
b) Calculate the SSTreatment, SSError, and SSTotal.
SSTOTAL: 11.278
SSTREATMENT: 3.648
SSERROR: 7.630
c) Complete the ANOVA Table below:
Source SS Df MS F0
Treatment 3.648 3-1 = 2 3.648/2 =
1.824 3.59
Error 7.630 3(6-1) =
15 7.630/15
= 0.509
otal 11.278 17
Worth 2
points
Worth 3 points: each one SS worth 1 point
Worth 3 points:
each df, MS and F
worth 1/2 point each
