The KDC40 is a small and cost-effective DC gridded ion source product. A new design and upgrade to the popular 3cm Kaufman source, it has a larger grid pattern, is more rugged, and has the ability to be outfitted with self-aligned three-grid ion optics. The KDC40 can perform all the typical ion-beam processes, including in-situ preclean, ion-beam surface modification, ion-beam-assisted deposition, ion-beam sputter deposition, ion-beam etching, and direct deposition. It is compatible with inert and reactive gases, including O2 and N2. The versatility of the KDC40 justifies its place in the process tool set of any laboratory where device fabrication involves thin-film deposition and plasma etching. Under the standard configuration, the typical ion energy range is from 100 to 1200eV, while the ion current can exceed 120mA.
|Discharge||DC Magnetic Confinement|
|- Filament Cathodes||One|
|- Anode Voltage||0-100V VDC|
|- Grids||Application Specific|
|- Beam Size @ Grid||4cm (Typical)|
|Power controller||KSC 1202|
|- Cathode / Neutralizer||Filament, Sidewinder Filament or LFN1000|
|- Mount||Remote or Direct Flange|
|- Height (Nominal)||6.75″|
|- Diameter (Nominal)||3.5″|
|- Materials Processed||Metals, Dielectrics, Semiconductors|
|- Process Gases||Inert, Reactive, Blends|
|- Typical Installation Distance||6-18″|
|- Process (Typical)||PC, SM, IBAD, IBE, IBSD|
|- Auto Controller||Controls up to 4 Gases with Blending Capabilities and Recipe Storage|
|- Ion Optics||Collimated, Focused, Defocused|
Beam Shaping Ion Optics
The KDC products offer a variety of ion optics designs. These designs determine the spatial distribution of ion current density downstream from the grid exit plane. With defocused ion optics design, the ions diverge as they exit the source, spreading the ion beam as they travel downstream. With a focused ion optics design, the ions converge to a focal point downstream of the grid exit plane. With a collimated ion optics design, the ions exit the grid with a trajectory nearly parallel to the ion source axis. These unique beam shapes are then matched to the appropriate ion beam process.
Decoupled Ion Energy and Current
For most of the operational range, the KDC products allow independent operation of important ion beam properties. For example, the ion energy and ion current can be set without a mutual interaction between the two parameters. The flexibility to interchange the ion energy (Vb) and ion current (Ib) at a given ion beam power (Pb = Vb x Ib), brings a valuable tool in process optimization. The KDC products produce an ion beam with essentially a mono-energetic ion energy distribution. Whether a substrate surface is bombarded with 200eV ion or 1000eV ions will influence the ion/material interaction. The KDC products output stable ion beam currents with variations typically less than 1% from the set-point. Whether a substrate surface is bombarded with a current of 1mA or 1000mA will influence process rates and temperature.
High Density DC Discharge
The KDC products utilize a well-proven and efficient plasma generation process. In the discharge chamber, a cathode thermionically emits a reliable source of electrons. The electrons are attracted to a DC biased metal anode. The neutral gas species is efficiently ionized due to a confining magnetic field. This mechanism produces a high density plasma of many gases, including Ar, Xe, O2, N2 and other reactive gases.
The standard KDC neutralizer configuration is an inexpensive refractory metal filament stretched across the ion beam. The filament is heated to thermionic emission temperature. The filament neutralizer may be replaced with an alternative non-immersed neutralizer. The non-immersed neutralizer sits to the side of the source and outside the ion beam. When the neutralizer is outside the beam, the time between maintenance is significantly longer for the non-immersed neutralizer versus the filament neutralizer. This non-immersed configuration is suited for low frequency maintenance installations and long operational runs when it is important to minimize the risk of process interruption.
Self-Aligning Grids (OptiBeam™)
The KDC product line incorporates KRI’s patented self-aligned ion optics technology. The OptiBeam™ grids do not require an alignment procedure. Through advanced engineering and precision construction, the straightforward assembly procedure assures the grids are aligned. The benefits of the self-aligning grids includes beam repeatability, extended grid lifetime, maximized ion current, reduced maintenance time and improved uptime.
The KDC product line provides a dedicated and regulated electron source neutralizer. With a reliable source of electrons, the KDC products can process dielectric, electrically isolated, and electrostatic sensitive substrates. The amount of electrons is precisely controlled to match positive charges. The correct amount electrons are present in the ion beam and they arrive at the substrate surface to provide an electrically neutral process. The KDC operation does not need to rely on an ambiguous source of electrons such as exposed and conductive chamber hardware. Coating build-up and stray electromagnetic fields, which may be present in the vacuum chamber, will not disturb the ion beam quality, stability or neutralization of the KDC products. However, in the case, when the neutralization process is not so critical, the KDC products do allow operation without the neutralizer.