Beamline architectures

There are elements of beamlines that are generally common among the three major types of implanters. All beamlines begin with an ion source and extraction optics, responsible for injecting an appropriately shaped beam of ions into the subsequent 

In multiwafer configurations, which are common for high current tools, the wafers typically are mounted onto a rotating disk, which is then linearly translated across the ion beam. The rotation of the disk ensures that each wafer passes completely out of the beam in the direction of rotation. The linear translation must be at least as long as the wafer diameter plus the nominal beam diameter in that direction. Some high current configurations have the linear translation direction across the dispersive plane of the beam, while others have it across the nondispersive plane. Beam utilization efficiency (see Sect. 15.4) is directly coupled to the demands placed on this translation length. 

In single-wafer configurations, a fixed spot beam and two orthogonal linear translations of the wafer typically are used. Flexibility is generally provided to tailor the relative speed of scanning in each direction in order to achieve optimum 

Most ion implanters with the simple fixed-spot beamline described above also make use of a multiwafer, mechanically scanned type endstation to provide adequate wafer cooling and improve overall tool productivity (discussed in more detail in Sect. 15.4). A rendered drawing of a typical high current tool with a multiwafer batch endstation is shown in Fig. 15.2. 

Following this parallelizing element, the beam may also be electrostatically deflected once more to provide energy filtering. This filtering removes ions of unwanted energy that may have had coincidental paths through the beamline. 

---