Browse Prior Art Database

Automatic Parameter Warning System

IP.com Disclosure Number: IPCOM000110267D
Original Publication Date: 1992-Nov-01
Included in the Prior Art Database: 2005-Mar-25
Document File: 3 page(s) / 137K

Publishing Venue

IBM

Related People

Dhom, H: AUTHOR [+2]

Abstract

This article describes an Automatic Parameter Warning System (APWS) for analyzing particle data during the production of semiconductors as well as other data.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

Automatic Parameter Warning System

       This article describes an Automatic Parameter Warning
System (APWS) for analyzing particle data during the production of
semiconductors as well as other data.

      Particle values of the various production tools are regularly
measured and input to a "C" program module for statistical evaluation
with reference to robust statistics.  In response to undesirable
particle values, the APWS issues a warning message to the people
responsible for the tools concerned.

      APWS (see flowchart), running under MVS (multiple virtual
storage) control, is a software consisting of blocks corresponding to
the statistical routines to be carried out.  One of these blocks
contains, for instance, robust statistics which are used to evaluate
series of measurements with outliers.  Outliers are either unduly
high or low measuring values outside the normal scatter which cannot
be tracked down by standard methods.  As particle data contains
outliers, it has to be evaluated by robust statistical routines in
order to determine the relevant expectation value.  Another block
serves to test the situation expectation value of mean values in an
interval "Target Specification", and a third and a fourth to carry
out a statistical test for the expectation value of percentage and
standard deviation values.

      As the structure of the individual blocks is identical, it is
sufficient to describe the structure of one block, namely, the one
used for particle evaluation.  This block is composed of three
elements (a preprocessor, a C module and a message sender), according
to the input file of the APWS.

      This input file is a sequential data set in which the various
tool data items to be controlled are lumped together.  How this
sequential input file is created is insignificant.  It may be the
data extract of a PRODAT database system, a DB2* database system, an
ORACLE, or something similar.  However, each single record must have
a particular format, i.e., it must be known where the identifier of
the tools whose data is to be evaluated can be found.

      As the data of particular tools requires an appropriate
statistical method, there must also be a profile of the relevant
statistical quantities, such as probability of errors of a first
kind, hypotheses, etc.  The data file and the profile are input data
for the preprocessor.

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