Patent Application
20100098518
1. Field of the Invention
Embodiments of the present invention relate to a selectively sealing an opening in a vacuum chamber. More particularly, to selectively sealing an opening in an evacuable transfer chamber.
2. Description of the Related Art
Semiconductor processes for large area substrates in the production of flat panel displays, solar cell arrays, and other electronic devices include processes such as deposition, etching, and testing, which are conventionally conducted in a vacuum processing chamber. To increase fabrication efficiency and/or lower production costs of the various end uses of the processed substrate, the large area substrates are currently about 2,200 mm× about 2,600 mm, and larger. The substrates are typically transferred into and out of the vacuum processing chamber through a transfer chamber that functions as an atmospheric/vacuum interface and is generally referred to as a load lock chamber. The load lock chamber provides a staged vacuum between atmospheric pressure and a pressure within the vacuum processing chamber. In some systems, the load lock chamber may be configured as a transfer interface between a queuing system at ambient pressure and the vacuum processing chamber providing for atmospheric to vacuum substrate exchange. Likewise, processed substrates may be transferred out of the vacuum processing chamber to atmospheric conditions through the load lock chamber.
The openings in the vacuum processing chambers and the load lock chambers are generally sized to receive at least one dimension (i.e. width or length) of the large area substrate to facilitate transfer of the substrate. The chamber openings are configured to be selectively opened and closed by a door to facilitate transfer of the substrate and vacuum sealing of the chamber. The operation of the door and effective sealing of the opening creates challenges to making and using of the chambers.
Therefore, there is a need for a vacuum chamber door that addresses these challenges.
Embodiments of the present invention generally provide a door actuation assembly for a vacuum chamber sized for one or more large area substrates. In one embodiment, a vacuum chamber sized for a large area substrate is described. The vacuum chamber includes a housing comprising a body having at least one sealable port, a movable door coupled with the sealable port, and a door actuation assembly coupling the door and the housing. The door actuation assembly comprises first actuators coupled to the door for moving the door in a first direction, and second actuators for moving the door in a second direction, the second direction orthogonal to the first direction.
In another embodiment, a vacuum chamber sized for a large area substrate is described. The vacuum chamber includes a housing comprising a body having at least one sealable port, a movable door coupled with the sealable port, and a door actuation assembly coupling the door and the housing. The door actuation assembly comprises a pair of first actuators coupled to the door for moving the door in a first direction, a pair of linear guides coupled between opposing ends of the door and the housing, and a pair of second actuators coupled to the linear guides and movable with the door, for moving the door in a second direction orthogonal to the first direction.
In another embodiment, a method for selectively opening and closing a sealable port in a vacuum chamber for processing a large area substrate, wherein the vacuum chamber comprises a housing, a door associated with the sealable port, the door movably coupled to a linear guide on opposing ends thereof, and a moving mechanism having a pair of first actuators and a pair of second actuators is described. The method includes synchronously driving the first actuators coupled to the door, detecting a position of the door, returning a positional metric corresponding to the position of the door, and adjusting a moving speed of the first actuators based on the positional metric to ensure a longitudinal dimension of the door remains substantially orthogonal to a travel path of at least one of the linear guides coupled to the door.
So that the manner in which the above recited features of the present invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.
To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements disclosed in one embodiment may be beneficially utilized on other embodiments without specific recitation.
Embodiments described herein relate to a system and method for selectively sealing a chamber opening that is adapted to contain one or more large area substrates in low pressure conditions. In one embodiment, the chamber may be configured for transferring substrates to and from ambient atmosphere and a vacuum environment. Although some embodiments are exemplarily described for use in evacuable transfer chambers, such as load lock chambers or other chambers configured to provide an atmospheric/vacuum interface, some embodiments may be applicable for other chambers configured for other low pressure processes. Examples include, without limitations, processing chambers, testing chambers, deposition chambers, etch chambers, and thermal treatment chambers. Substrates, as described herein, include large area substrates made of glass, a polymer material, or other material suitable for forming electronic devices thereon, that are configured for flat panel display production, solar cell array production, and other electronic devices that may be formed on large area substrates. Examples include thin film transistors (TFT's ), organic light emitting diodes (OLED's ), and p-i-n junctions or other devices used in the manufacture of solar arrays and/or photovoltaic cells.
The load lock chamber 100 includes a pair of first actuators 116 that are coupled to the I/O door 122 and the support frame 105. Each of the first actuators 116 are linear actuators that may be driven electrically, hydraulically, pneumatically, and combinations thereof. Examples of the first actuators 116 include an air cylinder, an electromechanically-operated cylinder, a hydraulic cylinder, a mechanically operated cylinder, and combinations of the above. The first actuators 116 are configured to synchronously raise and lower the I/O door 122 in at least a vertical (Z) direction. The first actuators 116 are also adapted to move the I/O door 122 in a substantially parallel orientation relative to the port 123. To facilitate parallel lifting and lowering of the I/O door 122, the I/O door 122 is coupled to two linear bearing blocks 124 respectively mounted at two ends 125A and 125B of the I/O door 122. The linear bearing blocks 124 are mounted to the sidewalls 135 of the load lock chamber 100. In one embodiment, the first actuators 116 may be horizontally spaced apart from each other to ensure uniform vertical (Z directional) movement of the I/O door 122.
In addition to vertical movement, the I/O door 122 is also adapted to move horizontally (X direction) facilitated by a pair of second actuators 126 respectively mounted on the two lateral ends 125A and 125B of the I/O door 122. The horizontal actuator blocks 126 are operable to move the I/O door 122 either toward the first end 115 for closing the sealable port 123, or away from the first end 115 for opening the sealable port 123. The second end 120 may also include another I/O door, another pair of linear bearing blocks, and another pair of first and second actuators, all of which are not shown.
As shown in
In one embodiment, one or more position sensors 164 may also be coupled to each of the linear bearing blocks 124. The position sensors 164 are configured to transmit detection signals reflecting the respective positions of the lateral ends 125A and 125B of the I/O door 122 to a controller 166 coupled to each of the first actuators 116. In one embodiment, each sensor 164 may be a transducer, a Hall effect sensor, a proximity sensor, a linear encoder, such as encoder tape, and combinations thereof. In other embodiments, each of the first actuators 116 may include a position sensor (not shown), such as a rotary encoder or a shaft encoder adapted to provide a positional metric of each first actuator 116.
The controller 166 is also coupled to each of the second actuators 126. The controller 166 is adapted to receive a metric from each sensor 164 indicative of movement of the of the I/O door 122 relative to the bearing blocks 124. The controller 166 may process the movement information to control the directional movement and/or directional speed of one or both of the first actuators 116. The controller 166 is also adapted to receive positional information from the sensors 164 to actuate the second actuators 126 to facilitate horizontal movement of the I/O door 122. The lifting and lowering speed of each first actuator 116 can thereby be accurately controlled to prevent misalignment of the I/O door 122 relative to the bearing blocks 124 during lifting and lowering of the I/O door 122. The misalignment of the I/O door 122 relative to the bearing blocks 124 may occur if a single actuator is used to lift/lower the I/O door 122, in which case that actuator is disposed to be in contact with the center of the bottom of the I/O door 122. However, supporting the I/O door 122 with single actuator may cause a wobbling of the I/O door 122 over the course of the lifting/lowering thereof, especially when the I/O door 122 becomes much wider to accommodate the transfer of larger substrate. Such wobbling or misalignment might lead to jamming of linear bearing blocks 124.
In one embodiment, the first actuators 116 are adapted to maintain the horizontal plane (X direction) of the I/O door 122 in an orthogonal relation relative to the linear bearing blocks 124. For example, the linear bearing blocks 124 include a longitudinal axis A and the I/O door 122 includes a longitudinal axis B. Based on positional information from the sensors 164, an angle α of about 90° may be maintained during lifting and lowering of the I/O door 122. This prevents misalignment of the I/O door 122 during lifting and lowering.
In conjunction with
While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention thus may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.
