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ION IMPLANTATION AND RAPID THERMAL PROCESSING

ION IMPLANTATION AND RAPID THERMAL PROCESSING 10.9

Given that the beam is scanned in one dimension, mechanical wafer scanning of only one dimen-
sion is required. For this reason, medium-current beamline architectures are almost exclusively cou-
pled with single-wafer processing chambers.

10.3 ENDSTATION ARCHITECTURES

10.3.1 Multi-Wafer
High-current and high-energy architectures predominantly make use of a multi-wafer batch processing
chamber in which a large number of (typically 13 to 17) wafers can be implanted simultaneously in
any processing step. This type of processing is typically implemented with a spinning disk that pro-
vides two-dimensional mechanical scanning (one rotation and one linear translation) of the wafers
across the fixed-spot beam. Wafers are automatically loaded onto individual pads on the disk through
a vacuum loadlock. Each pad typically sits at an angle (typically about 5°) relative to the plane of
the disk itself and is coated with a compliant elastomer material (such as specially formulated room
temperature vulcanizing polymers, or RTVs) to allow for adequate heat transfer from the wafer to the
17
cooled disk and pad. Disk rotation typically occurs at a speed of approximately 1000 revolutions per
minute (rpm) at a nominal radius of approximately 650 mm, which is sufficient to maintain wafer
temperatures below about 80°C with beam powers of up to 2 to 3 kW. Liner disk translation speeds
can be up to approximately 100 mm/s over a travel of up to 400 mm (enough to allow a beam of
5
order 100 mm in size to be scanned completely off of a 300-mm diameter wafer). Multi-wafer batch
disks also typically allow implantation at incident angles that can be varied over approximately 10°
about two orthogonal axes. When operating at maximum throughput, a multi-wafer architecture can
process up to approximately 230 wafers per hour (Fig. 10.5).

10.3.2 Single-Wafer
Medium-current architectures have exclusively made use of a single-wafer processing chamber in
which only one wafer is implanted in any one processing step. This architecture is typically imple-
mented with a single scanning arm capable of linear motion at up to 150 to 200 mm/s over a range

FIGURE 10.5 A multi-wafer batch processing chamber, showing a
13-wafer process disk and multiaxis tilt capability.

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