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STRAY DEPOSITION SHIELD

IP.com Disclosure Number: IPCOM000007043D
Original Publication Date: 1993-Oct-01
Included in the Prior Art Database: 2002-Feb-20
Document File: 4 page(s) / 170K

Publishing Venue

Motorola

Related People

John Hawkins: AUTHOR [+2]

Abstract

Stray metal deposition inside metal sputtering equipment has always been a problem and'SF1 (Sputtered Films Inc.) equipment is no exception. A gap between the chuck and the gate valve shield allowing metal to be deposited on the gate valve seating surface, creating leaks when the chuck opens and behind the chuck, being deposited on the chuck bellows and the chuck back plate. This becomes a problem with out-gassing, affecting pump down and reflectivity. The other area that had stray metal dep- osition was the chamber walls, by way of another gap where the chamber shield mates to the gate valve shield, allowing metal to be deposited on the cham- ber walls. (Figure 1).

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MOTOROLA INC. Technical Developments Volume 20 October 1993

STRAY DEPOSITION SHIELD

by John Hawkins and Ray Campos

  Stray metal deposition inside metal sputtering equipment has always been a problem and'SF1 (Sputtered Films Inc.) equipment is no exception. A gap between the chuck and the gate valve shield allowing metal to be deposited on the gate valve seating surface, creating leaks when the chuck opens and behind the chuck, being deposited on the chuck bellows and the chuck back plate. This becomes a problem with out-gassing, affecting pump down and reflectivity. The other area that had stray metal dep- osition was the chamber walls, by way of another gap where the chamber shield mates to the gate valve shield, allowing metal to be deposited on the cham- ber walls. (Figure 1).

  The only effective way of cleaning these areas is to scrub the metal offwith Scotch-Brite and alcohol during target change (every 3 days). During the scmi- annual Preventive Maintenance procedure, the chuck assembly is disassembled, cleaned in KOH and dipped in HCL. Although these procedures cleaned the system, it was also time consuming and created particles. All ofwhich affected product and shortened

the life of the gate valve, turbo pump and RGA quadrapole.

  Two changes are made to contain the stray dep- osition. First, a step is machined in the gate valve shield where the chamber shield attaches to it; and three more screws are added to make the surface flush and eliminate any poss...