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Three-Sigma Control Limits
Photolithography Example P 183 . Photolithography is an important fabrication step
in semiconductor manufacturing procedure. In this procedure the important quality characteristic in hard bake ( to increase resist adherence an
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Introduction
In this course we will discuss statistical methods for the purpose
(1).Constructing quality control charts with the objective of controlling processes to produce
products of uniform quality and
(ii). Constructing sampling plans to determine
13.18 In the production of a certain chemical liquid, there are a number of impurities that
can be present to degrade the quality of the resulting product. Four specific impurities are
interest. 50 samples (one liter each) were collected, and the number o
Phase I Application of x and R Charts:
Typically, preliminary samples are used for constructing control limits. For example in the
hard-bake examples (See Example 6.1) rst 25 samples are used to compute control limits
for both x and R charts. Hence, such