# Question

A TiW layer is deposited on a substrate using a sputtering tool. Table 6E.14 contains layer thickness measurements (in angstroms) on 20 subgroups of four substrates.

(a) Setup x and R control charts on this process. Is the process in control? Revise the control limits as necessary.

(b) Estimate the mean and standard deviation of the process.

(c) Is the layer thickness normally distributed?

(d) f The specifications are at 450 + – 30, estimate the process capability.

(a) Setup x and R control charts on this process. Is the process in control? Revise the control limits as necessary.

(b) Estimate the mean and standard deviation of the process.

(c) Is the layer thickness normally distributed?

(d) f The specifications are at 450 + – 30, estimate the process capability.

## Answer to relevant Questions

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