Browse Prior Art Database

IMPROVED WAFER LIFT BLADE

IP.com Disclosure Number: IPCOM000007335D
Original Publication Date: 1995-Mar-01
Included in the Prior Art Database: 2002-Mar-15
Document File: 1 page(s) / 54K

Publishing Venue

Motorola

Related People

Harry Flitter: AUTHOR

Abstract

Existing SF1 lift blades run on SS bearing guide wheels. The blades run through the wheels and then through the boat ofwafers, lilting one up the chuck for deposition. This produces particles on the lift blade, which then collects a wafer for loading and comes in proximity to the waters waiting in the boat. Regular cleaning is scheduled to combat the partic- ulate problem, but alignment problems are offen a side effect.

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MO-LA Technical Developments Volume 24 March 1995

IMPROVED WAFER LIFT BLADE

by Harry Flitter

  Existing SF1 lift blades run on SS bearing guide wheels. The blades run through the wheels and then through the boat ofwafers, lilting one up the chuck for deposition. This produces particles on the lift blade, which then collects a wafer for loading and comes in proximity to the waters waiting in the boat. Regular cleaning is scheduled to combat the partic- ulate problem, but alignment problems are offen a side effect.

  The lift blades in use are made of a mild steel. This material in this application has high inertia and low stiffness. Blade wobble is ever-present and the blades are always bent to some degree, causing difficulty in the alignment procedures. Many times a less than perfect alignment is the best that can be done.

impossible to permanently bend. Distortion beyond the materials memory causes breakage. The blade is either straight or shattered.

  The wafer cut outs on the new blade hold the wafer much more securely than the old blade did with two pins. The new design can be tilted forward to 60" and the wafer does not fall.

f!

  The new system uses a carbon fiber lift blade that offers very low inertia and WV high stithress. Blade wobble and run-out are eliminated in this application. The particulate causing wheels are also eliminated, replaced by a stock precision Unislide assembly from Velmex, Inc. The slide assembly fits over the actuating cylinder with a few a...