Browse Prior Art Database

BACKSIDE LOADING MECHANISM FOR CONTAMINATION CONTROL

IP.com Disclosure Number: IPCOM000014022D
Original Publication Date: 1999-Oct-01
Included in the Prior Art Database: 2003-Jun-19

Publishing Venue

IBM

Related People

Authors:
C NGO DE HANEY TJ NEUMANN YL HSIAO J STEPHENSON

Abstract

Published is a design of a pallet that holds 20 substrate-carriers for use in an Ion Beam Etching system (Veeco RF-350s Microetch System). The 2-piece pallet designed for the backside loading/unloading of carriers is simple to use and can minimize particle contamination. Permanently molded elastomer to the pallet and O-ring screw holes were also used for uniform heat conducting and maintaining vacuum integrity. In a typical pallet design, substrates are loaded into the pallet by sliding them into multiple pieces of rails. The rails are then screws down onto the base plate from the top. This design create potential problems such as i) leaving the substrate exposed to particle contaminants, ii) carriers scratching the elastomer (used for heat conducting) and shortening its life time. To minimize these problems, a new pallet was developed with an backside loading/unloading mechanism. First, the many rail pieces are combined into a single frame made of stainless steel. During loading/unloading, the frame is placed upside down onto a loading fixture that holds it in a fixed position. Substrate carriers are slide upside down into the rails of the frame using a vacuum wand. After all carriers are loaded, the base-plate, made of aluminum to minimize weigh and for efficient heat conductance, is placed on top and screws down onto the frame. To prevent leakage into the vacuum chamber, screw holes are fitted with O-ring that seal the base-plate against the frame. This loading process minimizes handling of carriers and the substrates are not exposed to the screwing action. The Ion Beam etching process produces heat on the substrate carriers that needed to be conducted away to keep consistent etch rate and to prevent photoresist from being burnt. Typically, the elastomer sheets are used in between the carriers and pallet for heat conductance. However, because of inconsistent thickness of the elastomer sheets, uniform temperature throughout the whole pallet is hard to achieve. With the 2-piece pallet, a uniformly thick layer of elastomer is permanently molded on the base plate. This not only provides more uniform temperature throughout the pallet but also easier to clean and maintain. 1