Browse Prior Art Database

VACUUM WAND LATTICE BOAT

IP.com Disclosure Number: IPCOM000006254D
Original Publication Date: 1991-Dec-01
Included in the Prior Art Database: 2001-Dec-19
Document File: 2 page(s) / 102K

Publishing Venue

Motorola

Related People

Barrington B. Ross: AUTHOR

Abstract

The "Vacuum Wand Lattice Boat" is a quartz lattice structure designed for vacuum wand usage in the spike- emitter anneal processes (wafers lay tlat on the lattice boat and are annealed horizontally), it sits on a quartz frame resting on the diffusion cantilever. This dil?usion furnace boat provides an opening or a space for the backsides of wafers to be handled with a vacuum wand. This structure can also be used for any anneal process in which wafers are annealed horizontally and are loaded and unloaded with tweezers or vacuum wands. The capacity for each run is five four-inch wafers. The Vacuum Wand Lattice Boat is used in a clean room environment and is normally ran in an atmospheric diision tube.

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MOTOROLA INC. Technical Developments Volume 14 December 1991

VACUUM WAND LATTICE BOAT

by Barrington B. Ross

   The "Vacuum Wand Lattice Boat" is a quartz lattice structure designed for vacuum wand usage in the spike- emitter anneal processes (wafers lay tlat on the lattice boat and are annealed horizontally), it sits on a quartz frame resting on the diffusion cantilever. This dil?usion furnace boat provides an opening or a space for the backsides of wafers to be handled with a vacuum wand. This structure can also be used for any anneal process in which wafers are annealed horizontally and are loaded and unloaded with tweezers or vacuum wands. The capacity for each run is five four-inch wafers. The Vacuum Wand Lattice Boat is used in a clean room environment and is normally ran in an atmospheric diision tube.

  It was designed initially to eliminate the awkward wafer handling practices for the horizontal spike anneal process. Because of the prior art's awkwardness, silicon production and particle wafers were being contaminated and damaged. The new technology reduced these defects and increased yield.

  The lattice boat designed for vacuum wand usage was evaluated for particles using the Tencor Particle Scanner. The scanner measured particles on bare silicon the size of .5 microns before and after the anneal 27 particle wafers were annealed in the BPSG spiked-emitter anneal diffusion furnace at 900°C for 10 seconds. Aher anneal, they were manually pulled from the furnace (with a can- tilever closure plate tixture), and placed in a clean vertical quartz boat to cool. The wafers were divided into 3 different groups: A.) Tweezers using the prior art (3 trials)
B.) Vacuum wand using the prior art (3 trials) and C.) Vacuum wand using the new design (Vacuum Wand Lattice Boat). The results were as follows:

Group Average Particle Add-ons

A 261 B 32

c2 8

{3 trials/Group and 3 wafers/trial)

This experiment eliminated tweezers from this process.

0 Motorola. 1°C. ,991

  The next experiment...