Question 3:
In “Orthogonal Design for Process Optimization and ItsApplication to Plasma Etching”, an experiment is described todetermine the effect of flow rate on the uniformity of the etch ona silicon wafer used in integrated circuit manufacturing. Threeflow rates are used in the experiment, and the resulting uniformity(in percent) for six replicates is shown below.
Flow | Observations |
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 |
- Does flow rate affect etch uniformity? Use ? = 0.05.
- Do the residuals indicate any problems with the underlyingassumptions?
- Use the Kruskal-Wallis procedure with ? = 0.05 to test fordifferences between mean uniformity at the three different flowrates.
