Browse Prior Art Database

CRISPER/LOT BOX 6279

IP.com Disclosure Number: IPCOM000005735D
Original Publication Date: 1988-Oct-01
Included in the Prior Art Database: 2001-Oct-31
Document File: 3 page(s) / 100K

Publishing Venue

Motorola

Related People

Steve Chapman: AUTHOR

Abstract

With existing lot boxes that open on the top, the chance of particles being put on the wafers is great. Let's follow the steps on inspecting a four inch wafer. I choose the four inch wafer because they are easy to lift out and put back into the conventional boxes with one hand. Also, similar problems exist with different size wafers.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 50% of the total text.

Page 1 of 3

0 M

MOlOROLA Technical Developments Volume 8 October 1988

CRISPEFULOT BOX 6279

by Steve Chapman

   With existing lot boxes that open on the top, the chance of particles being put on the wafers is great. Let's follow the steps on inspecting a four inch wafer. I choose the four inch wafer because they are easy to lift out and put back into the conventional boxes with one hand. Also, similar problems exist with different size wafers.

   Inspecting a lot of four inch wafers starts off with opening the lot box and exposing the 50 or so wafers inside. The inspector reaches over the top of the wafers and retrieves a boat of wafers. While he reached over, the particles from his gloved hand probably showered down onto the wafers. During the inspection, often, the top is left open leaving the waferexposed to the environment. Particles are generated and stirred up by people traveling through the area. For example: reaching for the flow sheet sitting on a shelf above the wafers can be like a short thunderstorm. When the wafers are stored back into the box, any particles accumulated on the inside of the lid are dumped onto the wafers when the box is closed. This happens throughout the fab, ie. align, coat, bake, implant, etc.

   With the new lot box the from of the box opens down. The wafers are put in the box with the top of the boat in first. This way the bottom of the boat is handled and the back of the wafers face the opening. You handle the boat with a fork, like the ones used with quartz boats. Using a fork, the human hand never touches the boat. If a two boat box is used, the boat left inside is still protected even with the box ope...