Patent ID: 7318869
Filing Date: 2008-01-15
Classification: C23C,H01J,H01L

Abstract:
1. A system comprising: a deposition process chamber defined at least in part by a pedestal for supporting a substrate; and a movable shield surrounding at least a portion of a periphery of the pedestal, the shield being mounted to move along a linear path, the shield having a structure that creates a variable opening in the chamber when moved to different positions along the linear path, wherein the movable shield comprises a first aperture portion that creates a first variable conductance path and a second aperture portion that creates a second variable conductance path as the shield is moved along the linear path, the second variable conductance path created by the second aperture portion, when the-shield is at a first position along the path, forming a first opening that is larger than any second opening achievable by the first variable conductance path created by the first aperture portion when the shield is at any position along the path, wherein a size of an opening achieved by the first variable conductance path or the second variable conductance path determines a gas conductance, the first aperture portion and the second aperture portion being fixed in relation to one another such that, when the shield moves in any direction along the path, the first aperture portion and the second aperture portion move equal amounts; and a translator coupled to the shield, the shield being coupled to the translator such that the translator translates the shield in a linear direction along the path, wherein gas conductance is only through the first variable conductance path when the shield is at a second position along the linear path, and gas conductance is through the second variable conductance path when the shield is at the first position along the linear path, the translator being coupled to the shield to move the shield in a first direction and an opposite second direction, the first aperture portion and the second aperture portion being rigidly fixed in relation to one another so as to always move together in both the first direction and the second direction, wherein the movable shield and chamber are configured such that the first aperture portion creates the first variable conductance path as the translator moves the shield throughout a first movement range, and the second aperture portion creates substantially no conductance path as the shield is moved throughout the first movement range, and wherein the second aperture portion is configured to create the second variable conductance path to provide a substantial conductance path only when the shield is moved beyond the first movement range.