Wafer processing machine vacuum front end method and apparatus

A transfer module for a wafer processing apparatus having a vacuum chamber therein, a loading and unloading station in the vacuum chamber having a holder located therein for holding a wafer in a vertical orientation, comprising:

• a vacuum transfer chamber;
• a radially extendable wafer transfer arm pivotal about a vertical axis within the transfer chamber;
• a plurality of treatment stations disposed approximately in a horizontal plane about the vertical axis in the transfer chamber;
• a loading and unloading port communicating between the transfer chamber and the loading and unloading station of the wafer processing machine;
• two wafer cassette loadlock chambers each containing a rack for supporting a plurality of horizontally disposed wafers in a vertical stack therein, and having an interior selectively connectable through a sealable port to the transfer chamber;
• the treatment stations including a wafer aligning station having means thereat for generating signals containing information of rotational and eccentrical alignment of a wafer positioned thereat without physically contacting the wafer;
• the treatment stations also including a two section temperature treatment station, including a preheating section having wafer heating means thereat, a cooling section having wafer cooling means thereat, and a moveable wafer support for moving a wafer between a receiving position and each of the sections;
• a wafer uprighting station including a platen thereat having means for holding a wafer thereto, the platen being pivotally mounted in the transfer module to swing, and carry a wafer, through the loading and unloading port between a horizontal orientation in the horizontal plane in the transfer chamber to a vertical orientation in the holder in the loading and unloading station of the machine;
• and
• the transfer arm including an extendable member pivotally connected at an end thereof at the vertical axis and having a wafer engager at a free end thereof, the arm being operable to engage a wafer with the engager and pickup the wafer from, and deposit the wafer at, a receiving position at each of the treatment stations and in each of the racks of the loadlock chambers, and to transfer wafers among each of the receiving positions.

A method of handling and processing wafers comprising the steps of:

• providing a plurality of horizontally oriented wafers spaced in a vertical stack in at least one cassette module, including a first cassette module, in a vacuum environment in communication with a transfer chamber;
• moving a horizontally oriented wafer from the first cassette module to an aligning station in the transfer chamber and aligning the wafer thereat;
• moving the aligned wafer from the aligning station to a preheating station in the transfer module and heating the wafer to degas the wafer;
• moving the degassed wafer from the preheating station to an uprighting station in the transfer module;
• moving the wafer from a horizontal orientation at the uprighting station through a loading port to a vertical orientation in a loading station in a wafer processing machine;
• processing the wafer while in the vertical orientation in the wafer processing machine;
• moving the processed wafer from the vertical orientation in the loading station of the wafer processing machine through the loading port and to a horizontal orientation at the uprighting station;
• moving the wafer from the uprighting station to a cooling station in the transfer module and cooling the wafer thereat;
• and
• moving the wafer from the cooling station to a storage position in the cassette module.

A method of handling and processing wafers comprising the steps of:

• providing a plurality of wafers each in a horizontal orientation and vertically spaced from each other in a stack in a cassette module in a vacuum environment in selective communication with a transfer chamber;
• moving a wafer from the cassette module in the horizontal orientation to an aligning station in the transfer chamber and sensing the eccentric and rotational alignment of the wafer thereat;
• moving the wafer in the horizontal orientation from the aligning station in angular and axial alignment at a preheating station in the transfer module and heating the wafer at the preheating station to degas the wafer;
• moving the degassed wafer in the horizontal orientation from the preheating station to an uprighting station in the transfer module;
• moving the wafer from the horizontal orientation at the uprighting station through a loading port to a vertical orientation in a loading station of a wafer processing machine;
• processing the wafer while in the vertical orientation in the wafer processing machine;
• moving the processed wafer from the vertical orientation in the loading station of the wafer processing machine through the loading port and to the horizontal orientation at the uprighting station;
• moving the wafer from the uprighting station in the horizontal orientation to a cooling station in the transfer module and cooling the wafer thereat;
• and
• moving the wafer in the horizontal orientation from the cooling station to a horizontally oriented storage position in a cassette module.

A wafer processing apparatus comprising:

• a wafer processing machine having a main vacuum chamber therein, a plurality of workstations spaced at equal angular intervals in a vertical plane in a circle around a horizontal axis in the main chamber, the plurality of workstations including a plurality of processing stations and a loading and unloading station, a rotatable index plate in the main chamber and having a plurality of wafer holders thereon spaced at the equal angular intervals in a circle about the horizontal axis such that, as the plate is indexed, the holders are sequentially moved through the workstations and simultaneously positioned at different ones of the workstations;
• a transfer module having a vacuum transfer chamber therein, a plurality of treatment stations horizontally disposed in the transfer chamber, and a loading and unloading port communicating between the transfer chamber and the loading and unloading station of the wafer processing machine;
• a plurality of wafer cassette loadlocks each having a rack support therein configured to hold a plurality of wafers in a horizontal orientation vertically spaced in a stack therein, the loadlocks having an interior selectively connectable through a sealable opening to the transfer chamber of the transfer module;
• the treatment stations including:
• a wafer aligning station;
• a wafer preheating station having a wafer heater thereat,
• a wafer cooling station having a wafer cooler thereat, and
• a wafer uprighting station having an uprighting mechanism thereat configured to move a wafer carried thereby between a horizontal orientation in the transfer chamber to a vertical orientation in the loading and unloading station of the wafer processing machine;
• and
• a transfer arm in the transfer chamber operable to pickup a wafer from, to deposit the wafer at, and to transfer wafers among selected treatment stations and loadlocks.

A transfer module for a wafer processing apparatus having a vacuum chamber therein, a loading and unloading station in the vacuum chamber having a holder located therein for holding a wafer in a vertical orientation, the transfer module comprising:

• a vacuum transfer chamber;
• a radially extendable wafer transfer arm pivotal about a vertical axis within the transfer chamber;
• a plurality of treatment stations disposed approximately in a horizontal plane about the vertical axis in the transfer chamber;
• a loading and unloading port communicating between the transfer chamber and the loading and unloading station of the wafer processing machine;
• two wafer cassette loadlocks each containing a rack for supporting a plurality of horizontally disposed wafers in a vertical stack therein, and having an interior selectively connectable through a sealable gate to the transfer chamber;
• the treatment stations including a wafer aligning station having thereat sensors for determining rotational and eccentric alignment of a wafer positioned thereat without physically contacting the wafer;
• the treatment stations also including at least one temperature treatment station, including a preheating section having a wafer heater thereat and a cooling section having a wafer cooler thereat;
• a wafer uprighting station having a wafer holder thereat that is pivotally mounted in the transfer module and moveable to carry a wafer, through the loading and unloading port, between a horizontal orientation in the horizontal plane in the transfer chamber to a vertical orientation in the holder in the loading and unloading station of the machine;
• and
• the transfer arm including an extendable member pivotally connected at an end thereof at the vertical axis and having a wafer engager at a free end thereof, the arm being operable to engage a wafer with the engager and pickup the wafer from, and deposit the wafer at, a receiving position at each of the treatment stations and in each of the racks of the loadlocks, and to transfer wafers among each of the receiving positions.

A wafer processing apparatus comprising:

• a plurality of cassette modules having a loadlock chamber therein adapted to support a vertical stack of horizontally oriented wafers and each having a gate;
• a vertical carrousel type wafer processing machine having a vacuum chamber therein and a wafer loading and unloading port communicating with the vacuum chamber;
• and
• a vacuum front end module interconnecting the cassette modules at the gates thereof and the processing machine at the port thereof, a transfer chamber therein selectively communicable with the vacuum chamber and the loadlock chambers, a moveable transfer arm therein moveable to transfer wafers in a horizontal orientation about the transfer chamber and edgewise through the gates of the cassette module, an uprighting mechanism in the transfer chamber operable to transfer wafers axially through the port and between the horizontal orientation in the transfer chamber and a vertical orientation in the processing chamber.