Browse Prior Art Database

Wafer-Alignment Device

IP.com Disclosure Number: IPCOM000100819D
Original Publication Date: 1990-Jun-01
Included in the Prior Art Database: 2005-Mar-16
Document File: 3 page(s) / 64K

Publishing Venue

IBM

Related People

Chu, KL: AUTHOR

Abstract

An alignment device is described which provides a means of positioning a wafer, as used in semiconductor circuit fabrication, so as to be vertically centered. The device also locates a notch/flat section on the wafer to facilitate future maneuverability.

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This is the abbreviated version, containing approximately 74% of the total text.

Wafer-Alignment Device

       An alignment device is described which provides a means
of positioning a wafer, as used in semiconductor circuit fabrication,
so as to be vertically centered.  The device also locates a
notch/flat section on the wafer to facilitate future maneuverability.

      The wafer is placed at the center of the alignment device at
position 2, as shown in side view Fig. 1a, by means of vacuum end of
arm tooling 11.  The outer circumference of the wafer rests on four
plastic locating pins 12, as shown in Fig. 1b, when end-of-arm
tooling 11 is removed.  The design is such that during this
positioning operation, the circumference of the wafer always contacts
three locating pins no matter where notch/flat 13 is located during
this placement.

      The centering operation is provided by slide air cylinder 14
which drives stepping motor 15 from position 1 to position 2 along
linear slide 16, as shown in Fig. 1a. Vacuum is applied to vacuum
pick-up head 17 which is mounted on stepping motor 15 so as to pick
up the wafer.  The center of rotation of vacuum pick-up head 17 and
the center of the wafer are in the same center position.  As the
wafer is being held by vacuum pick-up head 17, stage assembly 18 is
lifted up by means of stage air cylinder 19, so as to clear the wafer
from locating pins 12.

      Stepping motor 15 starts to rotate the wafer until reflective
sensor 20 detects notch/flat 13, which is located on the
circumference of th...