Flow rate in Exercise 13-6. Use α = 0.01.

(a) Apply Fisher€™s LSD method with α = 0.05 and determine which levels of the factor differ.

(b) Use the graphical method to compare means described in this section and compare your conclusions to those from Fisher€™s LSD method.

Exercise 13-6

In €œOrthogonal Design for Process Optimization and Its Application to Plasma Etching€ (Solid State Technology, May 1987), G. Z. Yin and D. W. Jillie described an experiment to determine the effect of C₂F₆ flow rate on the uniformity of the etch on a silicon wafer used in integrated circuit manufacturing. Three flow rates are used in the experiment, and the resulting uniformity (in percent) for six replicates follows.

Transcribed Image Text:

Observations 3 C,F, Flow (ŠČCM) 6. 125 2.7 4.6 2.6 3.0 3.2 3.8 160 4.9 4.2 5.1 4.6 5.0 4.2 3.6 4.6 4.1 3.4 2.9 3.5 200