Low Energy Ion Implantation in Semiconductor Manufacturing

Application/Instrumentation: Low Energy Ion Implantation in Semiconductor Manufacturing
Developed at: BNL, New York; High Current Electronic Institute, Tomsk, Russia; Institute for Theoretical and Experimental Physics (ITEP), Moscow, Russia
Developed in: 2003-2010
Result of NP Research: Deceleration and trapping of antiparticles
Application currently being supported by: DOE Initiative for Proliferation Prevention (IPP) & Cooperative Research and Development Agreements (CRADA)
Impact/benefit to spin-off field: Plasma-less, electrostatic structures for ion beam deceleration

Gasless, Plasma-less, Electrostatic Structures for Deceleration, Separation, and Transportation of Intense Low Energy Ion Beams; Low Energy Ion Beam Propagator for Ion Implantation

The decelerating system is based on a long focus system and an electrostatic undulator. In simulations using the KOBRA3-INp code as well as the BEAMDULAC code developed in MEPhI (Moscow), a 10 KV carborane 2В10Н12 ion beam was decelerated down to 2 KV.

ITER Diagram ITER Image

What makes this undulator operation novel is the potential distribution on its electrodes, unlike “traditional” electrostatic undulators where all electrodes have the same potential but with interchanging polarity. Simulation of the combined system showed that a 0.75 mA carborane (C2B10H12+) ion beam was successfully extracted at 10 KV and decelerated down to 2 KV without space charge “blow-up” (beam expansion). The undulator is being fabricated. Simulations and experimental results of the long focus system are in excellent agreement.

Electrostatic Undulator

Since the invention of the transistor, trend has been to miniaturize semiconductor devices. Hence, ion energy needed for implantation decreased (shallow implantation is desired). But, due to space charge effects, forming and transporting ion beams is a rather difficult task. Xenon plasma “flood” is used in current technology to overcome the space charge problem. But, plasma generation introduces impurities with adverse effects on implanted wafers. Concept of plasma-less, electrostatic structures based on long focus system & undulator was develop for molecular ion beam deceleration from 10 to 2 KV, without any expansion of the beam envelope. The system designed for a ribbon beam can be utilized for low energy ion beam implantation.