Plasma etching is essential to the fine-line pattern transferin semiconductor processes

Chapter 12, Problem 52

(choose chapter or problem)

Plasma etching is essential to the fine-line pattern transferin semiconductor processes. The article Ion BeamAssistedEtching of Aluminum with Chlorine (J. ofthe Electrochem. Soc., 1985: 20102012) gives theaccompanying data (read from a graph) on chlorine flow(x, in SCCM) through a nozzle used in the etching mechanismand etch rate (y, in 100 A/min).x 1.5 1.5 2.0 2.5 2.5 3.0 3.5 3.5 4.0y 23.0 24.5 25.0 30.0 33.5 40.0 40.5 47.0 49.0The summary statistics are oxi 5 24.0, oyi 5 312.5,oxi2 5 70.50, oxiyi 5 902.25, oyi2 5 11,626.75, b0 56.448718, b1 5 10.602564.a. Does the simple linear regression model specify auseful relationship between chlorine flow and etchrate?b. Estimate the true average change in etch rate associatedwith a 1-SCCM increase in flow rate using a95% confidence interval, and interpret the interval.c. Calculate a 95% CI for mY?3.0, the true average etchrate when flow 5 3.0. Has this average been preciselyestimated?d. Calculate a 95% PI for a single future observation onetch rate to be made when flow 5 3.0. Is the predictionlikely to be accurate?e. Would the 95% CI and PI when flow 5 2.5 be wideror narrower than the corresponding intervals of parts(c) and (d)? Answer without actually computing theintervals.f. Would you recommend calculating a 95% PI for aflow of 6.0? Explain.