| AVS 65th International Symposium & Exhibition | |
| Vacuum Technology Division | Monday Sessions |
| Session VT-MoM |
| Session: | Vacuum Measurement |
| Presenter: | Svetlana Radovanov, Applied Materials, Varian Semiconductor Equipment |
| Correspondent: | Click to Email |
Ribbon beam technology have been used in semiconductor ion implantation for past three decades. Over the years these ion implanters have become highly sophisticated tools incorporating the use of energy filters, collimators, quadrupoles, scanning systems and more recently molecular plasma sources, cryogenic and elevated implant temperature capabilities. One of the features that made these tools so successful in device fabrication is the high degree of control of the dopant depth profile. By selecting a unique ion mass, ion charge, ion energy and implant angle, a beam line tool offers highly automated control over the beam transport and implanted ion dose [1]. These beam lines operate with a large variety of species, several orders of magnitude energy and dose range. The wafer processed per hour reach 500 wafers/hour for a standard high current implanter. In recent years, some very high dose applications have been enabled by plasma doping systems [2]. For example, some dynamic random-access memory applications require incredibly high doses ~5x1016 /cm2 that can be done by plasma doping systems. Unlike the beam line tools, ions are not mass analyzed, but instead the wafer is processed within the plasma chamber or in an adjacent vacuum chamber. The wafer is pulsed negatively by a bias supply with a square wave T~50ms and f~5-50 kHz. Implant energy is controlled by the bias voltage which can exceed 10 kV. The plasma is generated by an inductively coupled rf coil. When the bias voltage is on, a plasma sheath forms in front of the wafer surface, across which ions are accelerated and are implanted into the silicon.
In this paper, we will discuss electrostatic focusing, filtering and steering of an ion beam and modeling associated with it. This will include low energy beam acceleration, deceleration and transport. We also describe the 2D and 3D codes that are used to model beam line optical elements.
REFERENCES
A. Renau, Review Scientific Instruments, 81, 02B907 (2010)
J. England and W. Moller, Nucl. Inst. Methods, 365, 105 (2015)