Reference no: EM132856994

Photoresist is a light-sensitive material applied to semiconductor wafers so that the circuit pattern can be imaged on to the wafer. After application, the coated wafers are baked to remove the solvent in the photoresist mixture and to harden the resist. Here are measurements of photoresist thickness (in kÅ) for eight wafers baked at two different temperatures. Assume that all of the runs were made in random order.

95 degree Celsius

11.176
7.089
8.097
11.739
11.291
10.759
6.467
8.315

100 Degrees Celsius

5.623
6.748
7.461
7.015
8.133
7.418
3.772
8.963

(a) Is there evidence to support the claim that the higher baking temperature results in wafers with a lower mean photoresist thickness? Use = 0.05.

(b) What is the P-value for the test conducted in part (a)?

(c) Find a 95% confidence interval on the difference in means. Provide a practical interpretation of this interval.