2.27. An article in Solid State Technoiogy. \"Orthogonal Design for Process Optimization and Its Application to Plasma Etching\" by G. 2. Yin and D. W. Jillie (May 1987) describes an experiment to determine the effect of the QR; flow rate on the uniformity of the etch on a silicon wafer used in integrated circuit manufacturing; All of the runs were made in random order. Data for two flow rates are as follows: _________ CZF' Flow Uniformity Observation (SCCM) l 2 3 4 5 6 .-_ 125 2.7 4.6 2.6 3.0 3.2 3.8 200 . 4.6 3.4 2.9 3.5 4.1 5.1 ___________ (a) Does the CZFI5 ow rate affect average etch uniformi- ty? Use a = 0.05. (b) What is the Pvalue for the test in pan (a)? (c) Does the th5 ow rate affect the wafertowafer vari- ability in etch uniformity? Use a: = 0.05. ((1) Draw box plots to assist in the interpretation of the data from this experiment